Description
Check whether a half-open date interval stays within one month.
Date labels and intervals depend on origins, endpoint inclusion and calendar versus elapsed-time conventions. Numeric serial periods and local token formats can represent useful bookkeeping without resolving a real instant or official fiscal rule.
Check whether a half-open date interval stays within one month.
When to use this tool
Use Calendar Interval Single Month Containment when checking a supplied date-label, duration or interval convention.
How to use the tool and how it works
- Enter start, endExclusive. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read contained, empty. Inspect contained, empty before interpreting the associated values.
Check whether a half-open date interval stays within one month. Validate start <= endExclusive; empty intervals are contained, otherwise compare start's month/year with the day before endExclusive.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| start | Start | Required. Text; maximum UTF-16 length 8192. Real proleptic Gregorian YYYY-MM-DD; four-digit years 0000-9999 accepted. |
| endExclusive | End Exclusive | Required. Text; maximum UTF-16 length 8192. Real proleptic Gregorian YYYY-MM-DD; four-digit years 0000-9999 accepted. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| contained | Empty half-open interval is always treated as contained; otherwise compare start with the final included day. | Required. Boolean. |
| empty | Empty | Required. Boolean. |
{
"input": {
"start": "2026-10-01",
"endExclusive": "2026-11-01"
},
"output": {
"contained": true,
"empty": false
}
}Limitations and assumptions
- An exclusive endpoint on the next month's first day does not itself cross the counted interval.
- 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 a complete date/time implementation and the applicable calendar policy for actual scheduling and interval interpretation.
References
Similar or alternative tools
- Calendar Week Span Overlap
Return overlap of two fixed seven-day spans.
- Date Interval Single Day Closure Label
Count civil days under a supplied endpoint convention.