Description
Convert a bounded Gregorian ordinal day to a civil date.
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.
Convert a bounded Gregorian ordinal day to a civil date.
When to use this tool
Use Ordinal Day Leap Boundary Crosswalk when checking the stated weekday or Gregorian calendar convention.
How to use the tool and how it works
- Enter year, ordinal. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read date. Use the output convention below.
Convert a bounded Gregorian ordinal day to a civil date. Require year in [1,9999] and ordinal in [1,366]; construct the UTC date and reject rollover outside that year.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| year | Year | Required. Safe integer; minimum 1; maximum 9999. |
| ordinal | Ordinal | Required. Safe integer; minimum 1; maximum 366. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| date | Date | Required. Text; maximum UTF-16 length 8192. |
{
"input": {
"year": 2024,
"ordinal": 60
},
"output": {
"date": "2024-02-29"
}
}Limitations and assumptions
- Day 366 is valid only in leap years; no timezone or alternative historical calendar is used.
- 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
- Era Boundary Day Gap
Return elapsed days from a supplied era boundary.
- Date: Ordinal Date Field Split
Parse a Gregorian ordinal-date token.