Description
Measure signed calendar days between a supplied due date and return date.
Library records distinguish copies, serial issues, leaf counts, field-state labels and edition-specific rights notes. A leaf may have two potential sides without both being printed or numbered. Due-date and hold-renewal arithmetic uses supplied calendar conventions rather than determining lending terms or access rights.
Measure signed calendar days between a supplied due date and return date.
When to use this tool
Use Library Circulation Due Return Gap when you already have suppliedDueDate, recordedReturnDate and need to measure signed calendar days between a supplied due date and return date.
How to use the tool and how it works
- Enter suppliedDueDate, recordedReturnDate. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read signedCalendarDays. Use the output convention below.
Parse real UTC dates; return recordedReturnDate-suppliedDueDate in days.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| suppliedDueDate | Supplied Due Date | Required. Text; maximum UTF-16 length 8192. Real proleptic Gregorian YYYY-MM-DD; four-digit years 0000-9999 accepted. |
| recordedReturnDate | Recorded Return 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 |
|---|---|---|
| signedCalendarDays | Signed Calendar Days | Required. Safe integer. |
{
"input": {
"suppliedDueDate": "2026-10-28",
"recordedReturnDate": "2026-11-01"
},
"output": {
"signedCalendarDays": 4
}
}Limitations and assumptions
- Positive means later than the supplied due date; no grace period, fine, opening-day rule or actual loan terms are determined.
- 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
Check the catalogue, physical item, field definition and original rights or lending record for actual status. Use the relevant complete cataloguing or calendar rule when a source label or supplied date offset is insufficient.
References
Similar or alternative tools
- Hold Request Expiry Renewal Margin
Extend a hold expiry by supplied calendar days and measure remaining days.
- Library Copy Withdrawn Lost Code
Label a library copy's recorded availability or withdrawal status.