Time & Date Calculators

Calculate working hours, time card totals and invoice due dates with practical time and date tools. Each calculator shows the information used and provides a clear breakdown of the result.

Choose a calculator below for work-hour calculations or to work out a payment due date from an invoice date and payment terms.

Time & Date Calculators

Time Card Calculator

Calculate hours worked from start and end times, including unpaid breaks and one-week or two-week time cards.

Calculate time card hours →

Invoice Due Date Calculator

Calculate an invoice due date from the invoice date and payment terms, including calendar days, business days and optional weekend adjustments.

Calculate an invoice due date →

Which time or date calculator should I use?

Use the Time Card Calculator when you need to total working time from clock-in and clock-out times. It can subtract unpaid breaks, calculate daily hours and total a one-week or two-week time card.

Use the Invoice Due Date Calculator when you know an invoice date and payment terms such as Net 15, Net 30, Net 60 or another number of days. It can calculate using calendar days or Monday-to-Friday business days and can optionally adjust a weekend due date.

Calculating working time

Working-time calculations usually begin with a start time and an end time. Any unpaid break is then deducted to find the amount of paid or recorded working time for that period.

When several days are involved, calculating each day separately before adding the totals can make it easier to identify missing hours, different shift lengths or unpaid breaks. The Time Card Calculator performs these calculations for each entered workday and provides a combined total.

Calculating dates from payment terms

A due-date calculation starts with a known date and adds the number of days specified by the payment terms. For example, standard Net 30 terms are commonly calculated by adding 30 days to the invoice date.

It is important to distinguish between calendar days and business days. Calendar-day calculations include Saturdays and Sundays, while the business-day option in CalcAtlas counts Monday to Friday only.

Public holidays are not automatically excluded because holiday dates and rules vary by country and region. Contracts, purchase orders and payment agreements may also define their own method for determining a due date.

Important considerations for time and date calculations

Time and date calculations can depend on the rules that apply to a particular situation. Workplace policies may determine which hours and breaks are paid, while contracts or payment agreements may specify how invoice terms should be counted.

CalcAtlas calculators perform the mathematical calculation from the information you enter. Where a result depends on employment rules, company policies, contractual terms, public holidays or local requirements, check the rules that apply to your own situation.

Time & Date Calculators