19 date & time tools
Date & Time tools
Find your place in the calendar.
Available Date & Time tools
Date Calculator
Free date calculator to add or subtract whole days, months, or years from a starting date and see the resulting calendar date.
Days Between Dates Calculator
Count the exclusive days, weeks, and hours between two dates.
Hours Calculator
Find net working hours from a start time, end time, and break.
Time Duration Calculator
Find the duration between two times, including overnight.
Business Days Calculator
Count weekday-only days between two dates, both inclusive.
Countdown Calculator
Count down the days, hours, minutes, and seconds to a future date.
Time Zone Converter
Convert a date and time between common time zones.
Days From Today Calculator
Find how many calendar days a date is from today.
Week Number Calculator
Find the ISO week number and week-year for any calendar date.
Day of the Week Calculator
Find which weekday matches any date.
Workday Calculator
Add or subtract weekdays from a starting date.
Work Time Card Calculator
Calculate net shift time after subtracting an unpaid break.
Date Difference with Time Calculator
Calculate the elapsed time between two dates and clock times.
Meeting Time Overlap Planner
Find the overlap between two manually entered work windows.
Pomodoro Timer
Run alternating focus and break cycles in your browser.
Date Recurrence Planner
Generate a bounded list of recurring calendar dates.
Monthly Calendar Generator
Create a simple month calendar ready to print or download.
Timesheet Calculator
Total multiple daily shifts, breaks, and overnight work hours.
Study Session Planner
Plan subjects, study durations, breaks, and an optional start time.
Helpful answers
Frequently Asked Questions
Useful details that apply across BiyoTool’s date & time tools.
No. Workday calculations skip Saturday and Sunday but do not load national, regional, or company holiday calendars.
Calendar-only tools use stable calendar-date rules, while time-zone tools use the selected zones. When a local time is skipped or repeated during a daylight-saving transition, the relevant tool may reject it rather than silently guess.