Description
Add integer offsetMinutes to the supplied hour and minute using exact integer arithmetic.
Clock arithmetic wraps at the end of a day. A fixed offset can move a time into a prior or following day without implying any timezone or daylight-saving rule.
Add integer offsetMinutes to the supplied hour and minute using exact integer arithmetic.
When to use this tool
Use Family Contact Safe Clock Offset when you need an explicit clock offset or elapsed watch-time calculation.
How to use the tool and how it works
- Enter hour, minute, offsetMinutes. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read dayOffset, hour, minute. Use the output convention below.
Add integer offsetMinutes to the supplied hour and minute using exact integer arithmetic. Normalize to a 24-hour clock with a signed dayOffset, including negative carries.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| hour | Hour | Required. Safe integer; minimum 0; maximum 23. |
| minute | Minute | Required. Safe integer; minimum 0; maximum 59. |
| offsetMinutes | Offset Minutes | Required. Safe integer. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| dayOffset | Signed whole-day offset accompanying the normalized clock. | Required. Safe integer. |
| hour | Hour | Required. Safe integer. |
| minute | Minute | Required. Safe integer. |
{
"input": {
"hour": 23,
"minute": 45,
"offsetMinutes": 90
},
"output": {
"dayOffset": 1,
"hour": 1,
"minute": 15
}
}Limitations and assumptions
- This is a fixed-offset calculation without dates, timezones, daylight-saving transitions, or contact-permission checks.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use a timezone-aware calendar library when real dates, daylight-saving changes, or civil-time scheduling matter.
References
Similar or alternative tools
- Navigation Watch Time Midnight Carry
Add shiftMinutes to minuteOfDay.
- Nautical Watch Bell Half Hour Index
For minutesSinceWatchStart in 0-240, return floor(minutes / 30) as bells, with zero before the first half-hour.