Predictable results
Date-only arithmetic
Calculations normalize calendar dates to UTC before comparing them. That keeps a “day” equal to 24 hours even when local clocks move for daylight-saving time.
Calculators
Date Calculator
Compare dates, move forward or backward in time, and count weekdays.
Choose a date calculation
Date-only arithmetic avoids daylight-saving and timezone shifts.
Weekday counting
Clear inclusion rules
The weekday result excludes the starting date and includes the ending date. Saturdays and Sundays are omitted, while public holidays remain included.
Common uses
Plan with calendar dates
How to use it
Get a reliable result
- Choose date difference or add/subtract mode.
- Enter the dates or day offset and select calendar days or weekdays.
- Review whether endpoints are included and copy the resulting date or count.
Useful for
Common workflows
- Estimate a project interval
- Find a date a set number of days away
- Count weekdays in a simple range without holidays
Examples
What to expect
Weekday shift
- Input
- Add 5 weekdays to a Monday
- Output
- The following Monday when no holidays are considered
Know before you start
Important limitations
- Weekday calculations do not include public, bank, school, religious, or company holidays.
- The tool uses calendar dates rather than hours and does not model time zones, daylight-saving transitions, or business hours.
- Results are planning aids and do not replace an official legal or contractual deadline calculation.
Common questions
Date Calculator FAQ
Are holidays excluded?
No. Weekday mode excludes Saturday and Sunday only. Use Business Days Calculator when custom holidays or weekend patterns matter.
Why can inclusive counts differ by one?
Including a boundary counts that calendar date; elapsed-day calculations normally count the transitions between dates.
Are dates uploaded?
No. Date-only arithmetic runs locally in this browser.
Browser-local
Processed on your device
All date calculations happen in this browser and are never uploaded.
How this processing works
The tool reads and processes this input in your browser. Tool Packer's application server does not receive the input or generated result.
Read the full privacy explanation