Description
Map an anniversary to a supplied year under a February-29 policy.
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.
Map an anniversary to a supplied year under a February-29 policy.
When to use this tool
Use Calendar Anniversary February Policy Flag when checking the stated weekday or Gregorian calendar convention.
How to use the tool and how it works
- Enter sourceDate, targetYear, policy. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read date, adjusted. Inspect adjusted before interpreting the associated values.
Map an anniversary to a supplied year under a February-29 policy. Validate sourceDate, targetYear 1-9999 and policy february28 or march1; adjust only a February 29 anniversary in a nonleap target year.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| sourceDate | Source Date | Required. Text; maximum UTF-16 length 8192. Real proleptic Gregorian YYYY-MM-DD; four-digit years 0000-9999 accepted. |
| targetYear | Target Year | Required. Safe integer; minimum 1; maximum 9999. |
| policy | Policy | Required. Text; one of "february28", "march1"; maximum UTF-16 length 8192. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| date | Date | Required. Text; maximum UTF-16 length 8192. |
| adjusted | Adjusted | Required. Boolean. |
{
"input": {
"sourceDate": "2024-02-29",
"targetYear": 2025,
"policy": "february28"
},
"output": {
"date": "2025-02-28",
"adjusted": true
}
}Limitations and assumptions
- The policy is supplied, not a legal birthday or anniversary rule.
- 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
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