Attach the day to each time
Fictional overnight coverage is day 1 22:00 to day 2 02:00, start included/end excluded. An observed interruption runs day 1 23:50 to day 2 00:20. It is entirely within coverage; the task measures minutes, not an annual uptime claim.
| Interval | Before midnight | After midnight |
|---|---|---|
| Coverage | 120 min | 120 min |
| Interruption | 10 min | 20 min |
| End boundary | Day 2 | 02:00 excluded |
Measure on one continuous line
- Order day-qualified timestamps
- Split once at midnight
- Sum the segment lengths
A time without a day is insufficient to decide an overnight order.
How long is the interruption and uninterrupted covered time?
Show the worked answer
30 interruption minutes and 210 uninterrupted minutes:10+20=30;240−30=210. An event at 02:00 is outside this window.
Check the closing boundary
| Case | Decision | Reason |
|---|---|---|
| 23:50 day 1→00:20 day 2 | 30 min | Dates retain forward order |
| Event at day 2 02:00 | Outside | End is excluded |
Keep both dates in the incident extract. A display showing only clock time cannot support this duration on its own.