Easily add or subtract days, weeks, months, and years to any date. Calculate business days with custom weekend exclusions.
🔒 Calculated right in your browser — start dates and values are never sent anywhere
Whether you're planning project milestones, calculating delivery schedules, checking visa expiration limits, or counting gestation periods, manual calendar math is prone to errors due to leap years and varying month lengths (28, 29, 30, or 31 days). This online Date Math Calculator does the exact arithmetic instantly. Simply input a start date, decide whether to add or subtract time, and get the exact result calendar-correct.
Often, project deadlines or official documents specify working days rather than calendar days. By enabling the Exclude Weekends option, you can count only weekdays. You can choose whether weekends consist of Saturday-Sunday, Friday-Saturday (standard in Bangladesh and parts of the Middle East), or single days, and the calculator will automatically skip those days during addition or subtraction.