DAYS360 Function (LibreOffice Calc)
The DAYS360 function calculates the number of days between two dates based on a 360-day year. It is commonly used in financial calculations, interest accrual, and accounting schedules.
Compatibility
▾| Excel | ✔ |
| Gnumeric | ✔ |
| Google_sheets | ✔ |
| Libreoffice | ✔ |
| Numbers | ✔ |
| Onlyoffice | ✔ |
| Openoffice | ✔ |
| Wps | ✔ |
| Zoho | ✔ |
What the DAYS360 Function Does ▾
- Calculates day differences using a 360‑day year
- Supports US (NASD) and European methods
- Normalizes end‑of‑month behavior
- Ideal for financial and accounting workflows
It is designed to be consistent, predictable, and aligned with industry standards.
Syntax ▾
DAYS360(start_date; end_date; [method])
Arguments
-
start_date:
The beginning date. -
end_date:
The ending date. -
method (optional):
FALSE or omitted → US (NASD) method
TRUE → European method
Method Comparison ▾
| Method | Behavior |
|---|---|
| US (NASD) | Adjusts end‑of‑month dates with special rules |
| European | Always treats months as 30 days, no special cases |
Basic Examples ▾
US method (default)
=DAYS360("2024-01-01"; "2024-02-01")
Returns 30.
European method
=DAYS360("2024-01-01"; "2024-02-01"; TRUE)
Returns 30.
Using cell references
=DAYS360(A1; B1)
Negative result (if reversed)
=DAYS360("2024-02-01"; "2024-01-01")
Returns -30.
Advanced Examples ▾
Interest accrual for a 30/360 bond
=Principal * Rate * DAYS360(Start; End) / 360
Days between month‑end dates (US method)
=DAYS360("2024-01-31"; "2024-02-28")
Returns 28 (US rules adjust Feb 28 → Feb 30).
Days between month‑end dates (European method)
=DAYS360("2024-01-31"; "2024-02-28"; TRUE)
Returns 30.
Days between two dynamic dates
=DAYS360(TODAY(); EOMONTH(TODAY(); 1))
Days in a financial quarter
=DAYS360(A1; EDATE(A1; 3))
Days between Excel serial dates imported as text
=DAYS360(DATE(1899;12;30)+VALUE(A1); DATE(1899;12;30)+VALUE(B1))
Days between ISO date strings
=DAYS360(DATEVALUE("2024-03-15"); DATEVALUE("2024-01-01"))
US vs European Method Details ▾
US (NASD) Rules
- If start_date is the 31st → treated as 30th
- If end_date is the 31st and start_date < 30 → end_date becomes 1st of next month
- If both dates are the 31st → both become 30th
European Rules
- Both dates’ day components are capped at 30
- No special end‑of‑month adjustments
Edge Cases and Behavior Details ▾
DAYS360 returns a number, not a date
Accepts:
- Real dates
- Serial numbers
- DATEVALUE outputs
Invalid text → Err:502
DAYS360 allows negative results
Time components are ignored
Leap years do not matter
360‑day calendar is artificial.
Common Errors and Fixes ▾
Err:502 — Invalid argument
Cause:
- Text not recognized as a date
- Non-numeric values
Fix:
- Wrap with DATEVALUE
- Clean text with TRIM or SUBSTITUTE
Unexpected results at month‑end
Cause:
- US method’s special rules
Fix:
- Use European method (
TRUE) for predictable behavior
Negative result unexpected
Fix:
- Reverse argument order
Best Practices ▾
- Use US method for US‑style financial instruments
- Use European method for international accounting
- Normalize text dates with DATEVALUE
- Use DAYS360 for interest, amortization, and accrual schedules
- Use DAYS for actual day counts
- Use YEARFRAC for fractional‑year calculations
DAYS360 is your financial‑calendar engine — perfect for interest accrual, amortization schedules, and any workflow requiring a standardized 360‑day year.
Related Patterns and Alternatives ▾
- Use DAYS for actual day counts
- Use DATEDIF for mixed-unit intervals
- Use YEARFRAC for fractional-year differences
- Use EDATE and EOMONTH for month offsets
- Use DATE for constructing comparison dates
By mastering DAYS360 and its companion functions, you can build precise, consistent, and finance‑ready date workflows in LibreOffice Calc.