Description
Return elapsed days from a supplied era boundary.
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.
Return elapsed days from a supplied era boundary.
When to use this tool
Use Era Boundary Day Gap when checking the stated weekday or Gregorian calendar convention.
How to use the tool and how it works
- Enter date, suppliedBoundaryDate. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read daysFromBoundary. Use the output convention below.
Return elapsed days from a supplied era boundary. Validate two date-only strings and divide their UTC-millisecond difference by 86400000.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| date | Date | Required. Text; maximum UTF-16 length 8192. Real proleptic Gregorian YYYY-MM-DD; four-digit years 0000-9999 accepted. |
| suppliedBoundaryDate | Supplied Boundary Date | Required. Text; maximum UTF-16 length 8192. Real proleptic Gregorian YYYY-MM-DD; four-digit years 0000-9999 accepted. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| daysFromBoundary | Days From Boundary | Required. Safe integer. |
{
"input": {
"date": "2024-01-03",
"suppliedBoundaryDate": "2024-01-01"
},
"output": {
"daysFromBoundary": 2
}
}Limitations and assumptions
- The boundary is caller-provided; historical eras, calendar reforms and local day lengths are not selected.
- 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.
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
- Ordinal Day Leap Boundary Crosswalk
Convert a bounded Gregorian ordinal day to a civil date.
- Calendar Quarter Day Position
Return a real date's calendar quarter and one-based day within it.