fix negative trend for calendar date

components/collector/src/collector_utilities/functions.py

@@ -82,7 +82,8 @@ def days_ago(date_time: datetime) -> int:
 
 def days_to_go(date_time: datetime) -> int:
     """Return the days remaining until the date/time."""
-    return (date_time - datetime.now(tz=date_time.tzinfo)).days
+    difference = (date_time - datetime.now(tz=date_time.tzinfo)).days
+    return difference if difference > 0 else 0
 
 
 def is_regexp(string: str) -> bool:

components/collector/tests/source_collectors/calendar/test_time_remaining.py

@@ -19,4 +19,4 @@ async def test_time_remaining(self):
     async def test_time_remaining_with_default(self):
         """Test the number of days without user-specified date."""
         response = await self.collect()
-        self.assert_measurement(response, value=str((datetime(2021, 1, 1) - datetime.now()).days))
+        self.assert_measurement(response, value="0")

docs/src/changelog.md

@@ -16,6 +16,7 @@ If your currently installed *Quality-time* version is v4.0.0 or older, please re
 
 ### Fixed
 
+- Prevent negative time remaining in the calendar source. Fixes [#5267](https://github.com/ICTU/quality-time/issues/5267).
 - Tags were not printed correctly in the reference manual. Fixes [#5282](https://github.com/ICTU/quality-time/issues/5282).
 - Prevent users from entering negative desired response times. Fixes [#5328](https://github.com/ICTU/quality-time/issues/5328).