From attendance to payroll — calculating LOP and payable days
24 September 2026 · 2 min read · by the DeskAttend team
Most payroll errors in small and mid-sized businesses start with attendance: a missed half day, unpaid leave recorded as paid, or a night shift counted as two broken days. Here is a clear way to calculate the two numbers your payroll tool needs.
The two numbers
- Loss of pay (LOP) days — days the person is not paid for.
- Payable days — the days they are paid for.
A common and easy-to-check definition:
LOP = absent days + unpaid leave days + ½ × half days
Payable days = days in the month − LOP
Weekly offs and holidays are paid, so they are not part of LOP.
A worked example
August has 31 days. An employee on a Monday–Friday shift has this month:
| Days | |
|---|---|
| Absent | 1 |
| Unpaid leave | 2 |
| Half days | 1 |
| Paid leave | 2 |
LOP = 1 + 2 + ½ × 1 = 3.5 Payable days = 31 − 3.5 = 27.5
Paid leave does not affect either number — it is paid.
Where it goes wrong
- Unpaid leave recorded as paid. It looks like leave either way, but it changes LOP. Keep unpaid leave as its own type.
- Half days forgotten. A half day is half a day of LOP.
- Night shifts split across two days. A 22:00–06:00 shift should count as 8 hours on the night it started. If the clock-out lands on the next day unpaired, the person appears absent.
- Time zones. If you have offices in more than one time zone, lateness and days must follow each person's local time.
Check it by hand once
Before trusting any tool, take one employee and one month and work the numbers out on paper. If they match, you can rely on the export; if not, find out why before salaries go out.
DeskAttend calculates LOP and payable days exactly this way — the maths is covered by automated tests using hand-worked months — and exports them for Zoho Payroll, RazorpayX and Tally.