📅 What is Date Calculator?
Date Calculator computes the duration between two dates or adds/subtracts days from a specific date. Use it for D-day countdowns, project deadlines, contract periods, and travel planning. Results are shown in multiple formats: days, weeks, hours, and years/months/days breakdown. Quick buttons let you apply common intervals (7, 30, 90 days) with one click.
📊 Date Calculation Use Cases
| Scenario | Mode | Example |
|---|---|---|
| D-day countdown | Date Difference | Days until exam/wedding? |
| Contract expiry | Add Days | 365 days from today? |
| Employment period | Date Difference | Days since start date |
| Backward planning | Subtract Days | When to book 30 days before trip? |
💡 Date Calculation Tips
- Business days: Subtract about 2/7 from total days for weekday estimate
- Leap years: Periods including Feb 29 have 366 days per year
- Time zones: For international dates, consider time zone differences
- Inclusive counting: Add 1 to include both start and end dates
Frequently Asked Questions
Does the date difference include the start and end dates?▼
The calculation subtracts start from end, so the start date is included but the end date is not. Add 1 to the result if you want both dates included.
How do I calculate a 100-day anniversary?▼
In "Add Days" mode, add 99 days to your start date (the day you met). Day 1 is the starting day, so day 100 is 99 days later.
Can I calculate past dates?▼
Yes, in "Add/Subtract Days" mode, enter a negative number to calculate past dates. For example, -30 gives you the date 30 days ago.
What is Date Calculator?
Calculate the number of days between any two dates. Add or subtract days, weeks, or months from a date. Find out what day of the week a date falls on.