Add / Subtract Time
What is an Add/Subtract Time Calculator?
The Add/Subtract Time Calculator allows you to perform arithmetic on dates. It answers questions like 'What date is exactly 45 days wafter today?' or 'What time was it 10 weeks ago?'. It's a simple but powerful utility for planning deadlines, scheduling follow-ups, or backtracking events.
Manually adding days is easy if it's within the same month (e.g., Jan 5 + 5 days = Jan 10). But adding 45 days to Jan 20th requires knowing whether it's a leap year, how many days represent February, and when March starts. This tool automates that calendar math instantly.
It supports multiple units of time—Days, Weeks, Hours, and Minutes—giving you flexibility for both long-term planning (dates) and short-term scheduling (times). The result is provided as a full date and time string tailored to your local format.
1How to Use
- Select Base Date: Pick a starting date and time from the picker (defaults to 'Now').
- Choose Operation: Select 'Add (+)' or 'Subtract (-)'.
- Enter Amount: Type the number you want to calculate (e.g., 30).
- Select Unit: Choose Days, Weeks, Hours, or Minutes.
- View Result: The black box at the bottom updates instantly with the new target date.
★Key Features
- Flexible Calculations: Add or subtract any amount of time.
- Multi-Unit Support: precision down to minutes or broad planning with weeks.
- Calendar Smart: Automatically handles month rollovers (Jan 31 + 1 day = Feb 1), leap years, and year changes.
- Instant Feedback: Results calculate in real-time as you type or change options.
- Local Formatting: Displays the result in your system's familiar date/time format.