Monthly & Semi-Monthly Time Card Calculator
Pick a month and it builds the real days for you — the right count, each with its weekday. Switch to semi-monthly to total just the 1st–15th or 16th–end.
All processing happens in your browser — your files never leave your device.How to use the monthly calculator
- Choose the month, year, and period. The rows rebuild instantly with the correct days and weekdays.
- For semi-monthly pay, set the period to 1st–15th or 16th–end to total just that half.
- Enter clock-in and clock-out per day; leave days off blank. Set breaks in minutes.
- Add rounding, overtime, and an hourly rate if you need a pay estimate.
- Print the month or export CSV — no account required.
Monthly vs. semi-monthly pay periods
These two schedules sound alike but pay differently. Monthly means one paycheck a month covering every day in that month — 12 checks a year. Semi-monthly means two checks a month on fixed dates, most often the 1st through the 15th and the 16th through the last day — 24 checks a year. Semi-monthly is not the same as biweekly: biweekly pays every two weeks and lands 26 checks a year on rotating weekdays.
Because semi-monthly halves start and end on calendar dates, the number of days in each half changes month to month. The first half is always the 1st to the 15th (15 days), while the second half runs from the 16th to the 28th, 29th, 30th, or 31st. This calculator generates the exact rows for whichever half you select, so you are never adding or deleting days by hand.
A note on overtime
Legal overtime in the United States is based on a fixed, recurring seven-day workweek, and a calendar month rarely lines up with those weeks. On this monthly view, overtime is grouped into seven-day blocks starting from the first day shown, which is an approximation. When you need overtime that matches a specific payroll workweek, total that week in the weekly calculator or the two weeks in the biweekly calculator instead.
Everything else works the same
Breaks in minutes come out of each shift, overnight shifts that cross midnight are handled automatically, and punch rounding follows the option you choose, including the 7-minute rule. Totals appear in hh:mm and decimal, and the whole month exports to CSV in one click.
Frequently asked questions
What is the difference between monthly and semi-monthly?
Monthly pay is one paycheck per month covering all days. Semi-monthly pay is two checks per month, usually for the 1st through the 15th and the 16th through the end. Use the period selector to switch between the full month and either half.
Does the calculator use the correct number of days for each month?
Yes. Pick a month and year and it builds the exact days, including 28 or 29 for February and 30 or 31 for other months, each labeled with its weekday.
How is overtime handled on a monthly card?
Overtime is grouped in seven-day blocks starting from the first day shown. Because legal overtime is based on fixed calendar workweeks, use the weekly or biweekly calculator when you need exact overtime for a specific workweek.
Will changing the month erase what I entered?
Changing the month, year, or period rebuilds the day rows and clears the entries, because the days are different. Reloading the same month keeps your entries, which are saved in this browser.
Can I print a monthly timesheet?
Yes. Press Print timesheet for a clean page with the month's rows and totals plus fill-in lines for a name and period. You can also export the whole month to CSV.
ShiftTally provides estimates to help you check your own hours and pay. Results are informational only and are not payroll, tax, or legal advice. Confirm figures against your official pay records.