Description
Clamp a source day to a supplied target-month length.
Civil calendar arithmetic needs explicit year numbering, leap rules and index origins. A weekday mask or Gregorian component operation does not identify a timezone, working calendar or historical calendar reform.
Clamp a source day to a supplied target-month length.
When to use this tool
Use Calendar Month End Subtraction Clamp Loss when checking the stated weekday or Gregorian calendar convention.
How to use the tool and how it works
- Enter sourceDay, targetMonthDays. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read targetDay, lostDays. Use the output convention below.
Clamp a source day to a supplied target-month length. Require sourceDay 1-31 and targetMonthDays 28-31; targetDay is their minimum and lostDays is the nonnegative difference.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| sourceDay | Source Day | Required. Safe integer; minimum 1; maximum 31. |
| targetMonthDays | Target Month Days | Required. Safe integer; minimum 28; maximum 31. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| targetDay | Target Day | Required. Safe integer. |
| lostDays | Lost Days | Required. Safe integer. |
{
"input": {
"sourceDay": 31,
"targetMonthDays": 28
},
"output": {
"targetDay": 28,
"lostDays": 3
}
}Limitations and assumptions
- No actual month subtraction, target year or calendar arithmetic is performed.
- 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 an appropriate full calendar library and authoritative local rules when business days, historical dates or real scheduling matter.
References
Similar or alternative tools
- Date: Calendar Month Length With Leap Flag
Return month length under a supplied leap-year flag.
- Calendar Month Ordinal Serial Pair
Return a serial month coordinate.