Add/subtract days
Add or subtract a number of days from a date — useful for working out a deadline, due date or a date a set number of days in the past.
Result
Result date
How to use this calculator
- Enter the starting date.
- Enter how many days to add — use a negative number to subtract.
- Read the resulting date.
Assumptions
- Counts calendar days, not business days — use the business days calculator if you need to skip weekends.
Technical details: what the fields mean
- Start date
startDate - The date to count from.
- Days to add (negative to subtract)
daysToAdd - How many days to add — enter a negative number (e.g. -14) to go backwards instead.
Methodology
Result date = start date + days to add (calendar days, accounting for month/year rollovers).
Worked example
1 Jan 2026 plus 30 days
Inputs: startDate=2026-01-01, daysToAdd=30
Result: 2026-01-31
Practical guidance
- For a working-day deadline (e.g. '10 business days from today'), use the business days calculator instead, since this counts every calendar day.
Common mistakes
- Using this for a business-day deadline (e.g. '5 working days') without accounting for weekends, since this counts every calendar day.
FAQs
How do I find the date 30 days from today?
Enter today's date and 30 in the days field — this calculator adds calendar days including weekends.