Description
Return secondEarliest-firstLatest, secondLatest-firstEarliest and inclusive interval overlap.
Historical records can use uncertain dates, different calendars and incomplete jurisdiction periods. Signed endpoint differences describe supplied coordinates; they do not perform a historical-calendar conversion or establish the actual period's authority.
Return secondEarliest-firstLatest, secondLatest-firstEarliest and inclusive interval overlap.
When to use this tool
Use Charter Dual Date Interval Gap when you need a supplied historical-date or interval comparison.
How to use the tool and how it works
- Enter firstEarliest, firstLatest, secondEarliest, secondLatest. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read minimumGap, maximumGap, overlap. Inspect overlap before interpreting the associated values.
Require ordered uncertain-date bounds. Return secondEarliest-firstLatest, secondLatest-firstEarliest and inclusive interval overlap.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| firstEarliest | First Earliest | Required. Safe integer. |
| firstLatest | First Latest | Required. Safe integer. |
| secondEarliest | Second Earliest | Required. Safe integer. |
| secondLatest | Second Latest | Required. Safe integer. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| minimumGap | Minimum Gap | Required. Safe integer. |
| maximumGap | Maximum Gap | Required. Safe integer. |
| overlap | Overlap | Required. Boolean. |
{
"input": {
"firstEarliest": 10,
"firstLatest": 20,
"secondEarliest": 15,
"secondLatest": 25
},
"output": {
"minimumGap": -5,
"maximumGap": 15,
"overlap": true
}
}Limitations and assumptions
- These are possible signed gaps on common numeric day coordinates, not probabilities or a historical-calendar conversion. Touching intervals count as overlap.
- 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
Resolve the source calendar, date precision and jurisdictional context before comparison. Use a dedicated historical chronology method when calendar conversion or legal interpretation is needed.
References
Similar or alternative tools
- Historic Jurisdiction Interval Gap
Return secondStart-minus-firstEnd and overlap when that difference is negative.
- European Cross Border Document Dual Date Label Tool
Display two explicitly transcribed calendar dates without calculating or asserting equivalence.