Date calculator: add or subtract calendar days
Choose a starting date and enter a positive number to move forward or a negative number to move backward. For example, adding 30 days to October 14, 2026 returns November 13, 2026. The tool works with calendar dates, so month lengths are handled by the browser date calculation.
Hours calculator: elapsed time
Enter a start and end time. If the end time is earlier than the start time, the tool treats it as an overnight span. A start of 9:00 and an end of 17:30 returns 8 hours 30 minutes.
Time Zone Converter: UTC offsets only
The converter moves the entered date and time from one selected UTC offset to another. For example, converting 09:00 from UTC to UTC+9 adds nine hours. It does not apply daylight-saving changes or location-specific historical rules. Use a time-zone database or the relevant organization’s schedule when daylight saving, travel, meetings, or deadlines are important.
Age calculator
The age tool compares the entered date of birth with the current date on the device running the page. It is intended for general reference; official eligibility or identity questions should use the applicable organization’s rules and records.