Dates: serve the display wall clock (wall_clock) to clients

Every payload a client renders a capture time from now carries
`wall_clock`, a naive ISO-8601 string computed by the existing
`date_view::row_display_wall`: the camera's wall clock (true instant +
camera offset; the owner's display zone without an offset), with the
per-source fallback for unconverted rows. Clients render it verbatim and
do no zone math, which is the FileViewer-React #33 / Apollo #37 flip with
the rule kept server-side: the drain's permanent `date_utc IS NULL` floor
(#120: edited/exported files) would otherwise force every client to
carry the per-source legacy conventions forever, and insight prompts
already use the same function, so prompt and UI agree by construction.

- `/image/metadata` (+ the GPS / date / date-clear mutation responses):
  `file_wall_clock` — the row's wall, else the filename-class date, else
  the earliest fs time in the display zone (unindexed files).
- `/memories` items and `/photos/gps-summary` photos: `row_wall_clock`.
- `get_all_with_gps` returns full rows instead of a 7-tuple that dropped
  `date_taken_source`, which unconverted rows need.
- `date_view::owner_display_zone` resolves prefs -> app default per request.

Legacy fields are untouched, so current clients see byte-identical
responses (additive; safe to deploy ahead of the client flip, per #120).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CLAUDE.md

@@ -467,6 +467,18 @@ are SMS-derived and unaffected. Progress: Prometheus
 `date_backfill_remaining` per library on `GET /libraries` (live count of
 `date_utc IS NULL`).
 
+**Displaying a capture time: `wall_clock`.** Every payload a client renders a
+capture time from (`/image/metadata` + the date/GPS mutation responses,
+`/memories` items, `/photos/gps-summary`) carries `wall_clock`, a naive
+ISO-8601 string (`2018-09-29T14:00:00`) computed by
+`date_view::row_display_wall` — the camera's wall clock (instant + camera
+offset; the owner's display zone when there's no offset), with the per-source
+fallback for rows the drain can't convert (its permanent floor).
+`file_wall_clock` covers files with no row yet (filename date, then fs time).
+Clients render it verbatim and do no zone math (ADR-0001; FileViewer-React #33,
+Apollo #37). Insight prompts use the same function, so prompt and UI agree.
+`dev/e2e/e2e.sh check` verifies it for every fixture on all three endpoints.
+
 `/memories` is a single SQL query against this column
 (`get_memories_in_window` in `src/database/mod.rs`), using
 `strftime('%m-%d' | '%W' | '%m', date_taken, 'unixepoch', tz)` for

src/data/mod.rs

@@ -259,6 +259,10 @@ pub struct MetadataResponse {
     pub filename_date: Option<i64>, // Date extracted from filename
     pub library_id: Option<i32>,
     pub library_name: Option<String>,
+    /// The capture wall clock to display, naive ISO-8601
+    /// (`2018-09-29T14:00:00`) — `date_view::file_wall_clock`. Render it
+    /// verbatim; never zone-convert it (ADR-0001).
+    pub wall_clock: Option<String>,
 }
 
 impl From<fs::Metadata> for MetadataResponse {
@@ -277,6 +281,7 @@ impl From<fs::Metadata> for MetadataResponse {
             filename_date: None, // Will be set in endpoint handler
             library_id: None,
             library_name: None,
+            wall_clock: None, // Set in the endpoint handler
         }
     }
 }
@@ -437,6 +442,9 @@ pub struct GpsPhotoSummary {
     /// Which evidence pinned the instant (`offset_tag`, `gps`,
     /// `assumed_server`, `utc_direct`, `manual`).
     pub date_taken_tz_source: Option<String>,
+    /// Capture wall clock to display (naive ISO-8601; see
+    /// `MetadataResponse::wall_clock`).
+    pub wall_clock: Option<String>,
 }
 
 #[derive(Debug, Serialize)]

src/database/mod.rs

@@ -389,25 +389,15 @@ pub trait ExifDao: Sync + Send {
     /// Get all file paths from EXIF database
     fn get_all_file_paths(&mut self) -> Result<Vec<String>, DbError>;
 
-    /// Get all photos with GPS coordinates
-    /// Returns Vec<(file_path, latitude, longitude, date_taken)>
-    #[allow(clippy::type_complexity)]
+    /// Get all rows with GPS coordinates (both latitude and longitude set)
+    /// under `base_path`. Full rows, so callers can apply the date contract
+    /// (`date_view`) — which needs the date source and path, not just the
+    /// new-contract triple.
     fn get_all_with_gps(
         &mut self,
         base_path: &str,
         recursive: bool,
-    ) -> Result<
-        Vec<(
-            String,
-            f64,
-            f64,
-            Option<i64>,
-            Option<i64>,
-            Option<i32>,
-            Option<String>,
-        )>,
-        DbError,
-    >;
+    ) -> Result<Vec<ImageExif>, DbError>;
 
     /// Return rows that still lack a `content_hash`, oldest first. Used by
     /// the `backfill_hashes` binary to batch through the historical
@@ -1168,23 +1158,11 @@ impl ExifDao for SqliteExifDao {
         .map_err(|e| DbError::log(DbErrorKind::QueryError, e))
     }
 
-    #[allow(clippy::type_complexity)]
     fn get_all_with_gps(
         &mut self,
         base_path: &str,
         recursive: bool,
-    ) -> Result<
-        Vec<(
-            String,
-            f64,
-            f64,
-            Option<i64>,
-            Option<i64>,
-            Option<i32>,
-            Option<String>,
-        )>,
-        DbError,
-    > {
+    ) -> Result<Vec<ImageExif>, DbError> {
         trace_db_call("query", "get_all_with_gps", |span| {
             use schema::image_exif::dsl::*;
 
@@ -1216,36 +1194,11 @@ impl ExifDao for SqliteExifDao {
                 .load::<ImageExif>(connection)
                 .map_err(|e| anyhow::anyhow!("GPS query error: {}", e))?;
 
-            // Convert to tuple format (path, lat, lon, legacy date_taken,
-            // date_utc, camera_offset_minutes, date_taken_tz_source).
-            // Filter out any rows where GPS is still None (shouldn't happen due to filter)
-            // Cast f32 GPS values to f64 for API compatibility
-            let filtered: Vec<(
-                String,
-                f64,
-                f64,
-                Option<i64>,
-                Option<i64>,
-                Option<i32>,
-                Option<String>,
-            )> = results
+            // The filter already requires both coordinates; keep the guard so
+            // callers can rely on lat/lon being present.
+            let filtered: Vec<ImageExif> = results
                 .into_iter()
-                .filter_map(|exif| {
-                    if let (Some(lat_val), Some(lon_val)) = (exif.gps_latitude, exif.gps_longitude)
-                    {
-                        Some((
-                            exif.file_path,
-                            lat_val as f64,
-                            lon_val as f64,
-                            exif.date_taken,
-                            exif.date_utc,
-                            exif.camera_offset_minutes,
-                            exif.date_taken_tz_source,
-                        ))
-                    } else {
-                        None
-                    }
-                })
+                .filter(|exif| exif.gps_latitude.is_some() && exif.gps_longitude.is_some())
                 .collect();
 
             span.set_attribute("result_count", filtered.len() as i64);

src/date_view.rs

@@ -184,6 +184,64 @@ pub fn row_display_day(
     )
 }
 
+/// Wire format for a wall clock: naive ISO-8601, no zone designator
+/// (`2018-09-29T14:00:00`). Clients render it verbatim — no zone math —
+/// so the UI shows exactly the wall [`row_display_wall`] computed and
+/// insight prompts use (ADR-0001: consumers never re-anchor).
+pub fn format_wall_clock(wall: NaiveDateTime) -> String {
+    wall.format("%Y-%m-%dT%H:%M:%S").to_string()
+}
+
+/// The owner's display zone for a request: prefs `display_tz`, else the
+/// app default (never fails — an unreadable prefs row is the default).
+pub fn owner_display_zone(
+    prefs_dao: &std::sync::Mutex<Box<dyn crate::database::UserAiPrefsDao>>,
+) -> Tz {
+    use std::str::FromStr;
+    let stored = prefs_dao
+        .lock()
+        .ok()
+        .and_then(|mut dao| dao.get_prefs().ok().flatten())
+        .and_then(|p| p.display_tz);
+    Tz::from_str(&camera_tz::display_zone_for(stored.as_deref()))
+        .unwrap_or(chrono_tz::Tz::America__New_York)
+}
+
+/// [`row_display_wall`] in wire format.
+pub fn row_wall_clock(
+    row: &ImageExif,
+    display_zone: Tz,
+    server_zone: Option<Tz>,
+) -> Option<String> {
+    row_display_wall(row, display_zone, server_zone).map(format_wall_clock)
+}
+
+/// Wall clock for a file that may have no `image_exif` row yet (not yet
+/// ingested, or excluded): the row's wall when it has one, else the
+/// filename-class date (a wall pattern *is* the wall; a unix-timestamp
+/// pattern renders in the display zone), else the file's earliest
+/// filesystem time rendered in the display zone. The same precedence the
+/// ingest waterfall applies, so the value doesn't jump once the row lands.
+pub fn file_wall_clock(
+    row: Option<&ImageExif>,
+    rel_path: &str,
+    fs_earliest: Option<i64>,
+    display_zone: Tz,
+    server_zone: Option<Tz>,
+) -> Option<String> {
+    if let Some(wall) = row.and_then(|r| row_display_wall(r, display_zone, server_zone)) {
+        return Some(format_wall_clock(wall));
+    }
+    let wall = match crate::memories::extract_date_from_filename(rel_path) {
+        Some(crate::memories::FilenameDate::Wall(wall)) => Some(wall),
+        Some(crate::memories::FilenameDate::Utc(dt)) => {
+            render_in_zone_opt(dt.timestamp(), display_zone)
+        }
+        None => fs_earliest.and_then(|t| render_in_zone_opt(t, display_zone)),
+    };
+    wall.map(format_wall_clock)
+}
+
 /// Render a unix instant as a naive wall in `zone`.
 fn render_in_zone_opt(instant: i64, zone: Tz) -> Option<NaiveDateTime> {
     zone.timestamp_opt(instant, 0)
@@ -564,4 +622,102 @@ mod tests {
         );
         assert_eq!(row_true_instant(&fs, tokyo, Some(ny())), Some(instant));
     }
+
+    #[test]
+    fn wall_clock_is_the_camera_wall_for_a_travel_zone_photo() {
+        // 14:00 in Tokyo (+09:00) = 05:00Z. The owner is in New York, but
+        // the wall clock is the camera's: 14:00, not 01:00.
+        let r = row(
+            "otd.jpg",
+            Some(utc_epoch(2018, 9, 29, 14, 0)),
+            Some("exif"),
+            Some(utc_epoch(2018, 9, 29, 5, 0)),
+            Some(540),
+        );
+        assert_eq!(
+            row_wall_clock(&r, ny(), Some(ny())),
+            Some("2018-09-29T14:00:00".to_string())
+        );
+    }
+
+    #[test]
+    fn wall_clock_without_offset_renders_the_instant_in_the_display_zone() {
+        // Container date (utc_direct): 12:30Z is 08:30 in New York (EDT).
+        let r = row(
+            "summit.mp4",
+            None,
+            Some("exiftool"),
+            Some(utc_epoch(2022, 8, 20, 12, 30)),
+            None,
+        );
+        assert_eq!(
+            row_wall_clock(&r, ny(), Some(ny())),
+            Some("2022-08-20T08:30:00".to_string())
+        );
+    }
+
+    #[test]
+    fn wall_clock_serves_unconverted_rows_by_their_legacy_convention() {
+        // The drain's permanent floor never gets date_utc; an `exif` legacy
+        // value is the wall stored as UTC and must come back unshifted.
+        let r = row(
+            "edited.jpg",
+            Some(utc_epoch(2021, 5, 12, 10, 30)),
+            Some("exif"),
+            None,
+            None,
+        );
+        assert_eq!(
+            row_wall_clock(&r, ny(), Some(ny())),
+            Some("2021-05-12T10:30:00".to_string())
+        );
+    }
+
+    #[test]
+    fn file_wall_clock_prefers_the_row() {
+        let r = row(
+            "Screenshots/Screenshot_20220315-101500.png",
+            Some(utc_epoch(2022, 3, 15, 10, 15)),
+            Some("filename"),
+            Some(utc_epoch(2022, 3, 15, 14, 15)),
+            Some(-240),
+        );
+        assert_eq!(
+            file_wall_clock(Some(&r), &r.file_path, Some(0), ny(), Some(ny())),
+            Some("2022-03-15T10:15:00".to_string())
+        );
+    }
+
+    #[test]
+    fn file_wall_clock_without_a_row_uses_the_filename_wall() {
+        assert_eq!(
+            file_wall_clock(
+                None,
+                "Screenshots/Screenshot_20220315-101500.png",
+                Some(0),
+                ny(),
+                Some(ny())
+            ),
+            Some("2022-03-15T10:15:00".to_string())
+        );
+    }
+
+    #[test]
+    fn file_wall_clock_without_a_row_or_filename_date_uses_fs_time_in_display_zone() {
+        // 2015-03-01 17:00Z = 12:00 in New York (EST).
+        assert_eq!(
+            file_wall_clock(
+                None,
+                "Undated/scan_01.jpg",
+                Some(utc_epoch(2015, 3, 1, 17, 0)),
+                ny(),
+                Some(ny())
+            ),
+            Some("2015-03-01T12:00:00".to_string())
+        );
+        assert_eq!(
+            file_wall_clock(None, "Undated/scan_01.jpg", None, ny(), Some(ny())),
+            None
+        );
+    }
 }

src/files.rs

@@ -1100,27 +1100,24 @@ pub async fn get_gps_summary(
     let mut exif_dao_guard = exif_dao.lock().expect("Unable to get ExifDao");
     match exif_dao_guard.get_all_with_gps(&requested_path, recursive) {
         Ok(gps_data) => {
+            let display_zone = crate::date_view::owner_display_zone(&app_state.user_ai_prefs_dao);
+            let server_zone = crate::camera_tz::server_zone();
             let mut photos: Vec<GpsPhotoSummary> = gps_data
                 .into_iter()
-                .map(
-                    |(
-                        path,
-                        lat,
-                        lon,
-                        date_taken,
-                        date_utc,
-                        camera_offset_minutes,
-                        date_taken_tz_source,
-                    )| GpsPhotoSummary {
-                        path,
-                        lat,
-                        lon,
-                        date_taken,
-                        date_utc,
-                        camera_offset_minutes,
-                        date_taken_tz_source,
-                    },
-                )
+                .filter_map(|row| {
+                    let wall_clock =
+                        crate::date_view::row_wall_clock(&row, display_zone, server_zone);
+                    Some(GpsPhotoSummary {
+                        lat: row.gps_latitude? as f64,
+                        lon: row.gps_longitude? as f64,
+                        path: row.file_path,
+                        date_taken: row.date_taken,
+                        date_utc: row.date_utc,
+                        camera_offset_minutes: row.camera_offset_minutes,
+                        date_taken_tz_source: row.date_taken_tz_source,
+                        wall_clock,
+                    })
+                })
                 .collect();
 
             // Sort by date_taken based on request, defaulting to ascending (oldest to newest)
@@ -1632,18 +1629,7 @@ mod tests {
             &mut self,
             _base_path: &str,
             _recursive: bool,
-        ) -> Result<
-            Vec<(
-                String,
-                f64,
-                f64,
-                Option<i64>,
-                Option<i64>,
-                Option<i32>,
-                Option<String>,
-            )>,
-            DbError,
-        > {
+        ) -> Result<Vec<crate::database::models::ImageExif>, DbError> {
             todo!()
         }
 

src/handlers/image.rs

@@ -524,11 +524,18 @@ pub async fn get_file_metadata(
                 .map(memories::FilenameDate::legacy_timestamp);
 
             // Query EXIF data if available
-            if let Ok(mut dao) = exif_dao.lock()
-                && let Ok(Some(exif)) = dao.get_exif(&path.path)
-            {
-                response.exif = Some(exif.into());
-            }
+            let row = exif_dao
+                .lock()
+                .ok()
+                .and_then(|mut dao| dao.get_exif(&path.path).ok().flatten());
+            response.wall_clock = crate::date_view::file_wall_clock(
+                row.as_ref(),
+                &path.path,
+                earliest_fs_time(&response),
+                crate::date_view::owner_display_zone(&app_state.user_ai_prefs_dao),
+                crate::camera_tz::server_zone(),
+            );
+            response.exif = row.map(Into::into);
 
             span.add_event(
                 "Metadata fetched",
@@ -706,8 +713,16 @@ pub async fn set_image_gps(
                     filename_date: None,
                     library_id: None,
                     library_name: None,
+                    wall_clock: None,
                 },
             };
+            response.wall_clock = crate::date_view::file_wall_clock(
+                Some(&row),
+                &normalized_path,
+                earliest_fs_time(&response),
+                crate::date_view::owner_display_zone(&app_state.user_ai_prefs_dao),
+                crate::camera_tz::server_zone(),
+            );
             response.exif = Some(row.into());
             response.library_id = Some(resolved_library.id);
             response.library_name = Some(resolved_library.name.clone());
@@ -848,6 +863,7 @@ fn build_metadata_response_for_date_mutation(
     library: &libraries::Library,
     rel_path: &str,
     exif: ImageExif,
+    display_zone: chrono_tz::Tz,
 ) -> MetadataResponse {
     let full_path = is_valid_full_path(&library.root_path, &rel_path.to_string(), false);
     let fs_meta = full_path
@@ -864,8 +880,16 @@ fn build_metadata_response_for_date_mutation(
             filename_date: None,
             library_id: None,
             library_name: None,
+            wall_clock: None,
         },
     };
+    response.wall_clock = crate::date_view::file_wall_clock(
+        Some(&exif),
+        rel_path,
+        earliest_fs_time(&response),
+        display_zone,
+        crate::camera_tz::server_zone(),
+    );
     response.exif = Some(exif.into());
     response.library_id = Some(library.id);
     response.library_name = Some(library.name.clone());
@@ -874,6 +898,15 @@ fn build_metadata_response_for_date_mutation(
     response
 }
 
+/// Earlier of the file's created / modified times — the ingest waterfall's
+/// `fs_time` rule — for the wall-clock fallback of unindexed files.
+fn earliest_fs_time(response: &MetadataResponse) -> Option<i64> {
+    match (response.created, response.modified) {
+        (Some(c), Some(m)) => Some(c.min(m)),
+        (c, m) => c.or(m),
+    }
+}
+
 #[post("/image/exif/date")]
 #[tracing::instrument(name = "set_image_date", skip_all)]
 pub async fn set_image_date(
@@ -924,6 +957,7 @@ pub async fn set_image_date(
                 library,
                 &normalized_path,
                 row,
+                crate::date_view::owner_display_zone(&app_state.user_ai_prefs_dao),
             ))
         }
         Err(e) => {
@@ -972,6 +1006,7 @@ pub async fn clear_image_date(
                 library,
                 &normalized_path,
                 row,
+                crate::date_view::owner_display_zone(&app_state.user_ai_prefs_dao),
             ))
         }
         Err(e) => {

src/memories.rs

@@ -164,6 +164,10 @@ pub struct MemoryItem {
     pub date_utc: Option<i64>,
     pub camera_offset_minutes: Option<i32>,
     pub date_taken_tz_source: Option<String>,
+    /// Capture wall clock to display, naive ISO-8601 (`row_display_wall`):
+    /// the camera's clock, which can differ from the owner's day that
+    /// `created` groups under. Render verbatim (ADR-0001).
+    pub wall_clock: Option<String>,
 }
 
 #[derive(Debug, Serialize)]
@@ -637,6 +641,7 @@ pub fn gather_memory_items(
             }
 
             let created = crate::date_view::row_true_instant(&row, display_zone, server_zone);
+            let wall_clock = crate::date_view::row_wall_clock(&row, display_zone, server_zone);
             memories_with_dates.push((
                 MemoryItem {
                     path: row.file_path,
@@ -646,6 +651,7 @@ pub fn gather_memory_items(
                     date_utc: row.date_utc,
                     camera_offset_minutes: row.camera_offset_minutes,
                     date_taken_tz_source: row.date_taken_tz_source,
+                    wall_clock,
                 },
                 display_day,
             ));
@@ -1130,6 +1136,7 @@ mod tests {
                     date_utc: None,
                     camera_offset_minutes: None,
                     date_taken_tz_source: None,
+                    wall_clock: None,
                 },
                 NaiveDate::from_ymd_opt(2024, 1, 15).unwrap(),
             ),
@@ -1142,6 +1149,7 @@ mod tests {
                     date_utc: None,
                     camera_offset_minutes: None,
                     date_taken_tz_source: None,
+                    wall_clock: None,
                 },
                 NaiveDate::from_ymd_opt(2020, 1, 15).unwrap(),
             ),
@@ -1154,6 +1162,7 @@ mod tests {
                     date_utc: None,
                     camera_offset_minutes: None,
                     date_taken_tz_source: None,
+                    wall_clock: None,
                 },
                 NaiveDate::from_ymd_opt(2021, 1, 16).unwrap(),
             ),
@@ -1484,6 +1493,7 @@ mod tests {
                 date_utc: None,
                 camera_offset_minutes: None,
                 date_taken_tz_source: None,
+                wall_clock: None,
             };
             let v: serde_json::Value =
                 serde_json::to_value(&MemoriesResponse { items: vec![item] }).unwrap();

src/reels/selector.rs

@@ -430,6 +430,7 @@ mod tests {
                 date_utc: None,
                 camera_offset_minutes: None,
                 date_taken_tz_source: None,
+                wall_clock: None,
             },
             memories::MemoryItem {
                 path: "b".into(),
@@ -439,6 +440,7 @@ mod tests {
                 date_utc: None,
                 camera_offset_minutes: None,
                 date_taken_tz_source: None,
+                wall_clock: None,
             },
             memories::MemoryItem {
                 path: "c".into(),
@@ -448,6 +450,7 @@ mod tests {
                 date_utc: None,
                 camera_offset_minutes: None,
                 date_taken_tz_source: None,
+                wall_clock: None,
             },
         ];
         assert_eq!(
@@ -466,6 +469,7 @@ mod tests {
             date_utc: None,
             camera_offset_minutes: None,
             date_taken_tz_source: None,
+            wall_clock: None,
         }
     }
     fn item_at(ts: i64, name: &str) -> memories::MemoryItem {