Add timespan calculation for day_obs on ingest

python/lsst/obs/base/ingest.py

@@ -45,6 +45,7 @@
     FileDataset,
     Formatter,
     Progress,
+    Timespan,
 )
 from lsst.pex.config import ChoiceField, Config, Field
 from lsst.pipe.base import Instrument, Task
@@ -306,6 +307,12 @@ def __init__(
         # have all the relevant metadata translators loaded.
         Instrument.importAll(self.butler.registry)
 
+        # Read all the instrument records into a cache since they will be
+        # needed later to calculate day_obs timespans, if appropriate.
+        self._instrument_records = {
+            rec.name: rec for rec in butler.registry.queryDimensionRecords("instrument")
+        }
+
     def _reduce_kwargs(self) -> dict[str, Any]:
         # Add extra parameters to pickle.
         return dict(
@@ -856,9 +863,12 @@ def makeDependencyRecords(
                 instrument=obsInfo.instrument,
             )
         if "day_obs" in exposure.implied:
+            instrument_record = self._instrument_records[obsInfo.instrument]
+            offset = instrument_record.day_obs_offset
             records["day_obs"] = universe["day_obs"].RecordClass(
                 instrument=obsInfo.instrument,
                 id=obsInfo.observing_day,
+                timespan=Timespan.from_day_obs(obsInfo.observing_day, offset),
             )
         return records
 

python/lsst/obs/base/instrument_tests.py

@@ -140,6 +140,9 @@ def register(self, registry, update=False):
             "visit_max": 1_000_000,
             "exposure_max": 1_000_000,
         }
+        if "day_obs_offset" in registry.dimensions["instrument"].metadata:
+            dataId["day_obs_offset"] = self.day_obs_offset
+
         with registry.transaction():
             registry.syncDimensionData("instrument", dataId, update=update)
             self._registerFilters(registry, update=update)