Add or subtract hours, minutes, and seconds. Calculate time from a specific date, or evaluate full time expressions. Fast, accurate, and completely free.
➕ Add Time➖ Subtract Time📅 Date + Time🔣 Expression Mode
⏱️
Add or Subtract Time Values
Add up to 5 time rows together
Operation:
Time 1
Time 2
📅
Add or Subtract Time from a Date
Find what date/time results after adding duration
Start Date & Time
Duration to Add / Subtract
Operation:
🔣
Time Expression Mode
Type a full time expression to evaluate
Enter Expression
Use: d = days h = hours m = minutes s = seconds
Operators: + add - subtract
Example: 1d 2h 30m + 45m - 20s
Result
4h 15m 0s
4 hours, 15 minutes, 0 seconds
0
Days
4
Hours
15
Minutes
0
Seconds
🔄 Result in All Units
Unit
Value
How to Use the Time Calculator
Our time calculator has three powerful modes. Use Add/Subtract to combine multiple time durations — great for tracking total work hours or project time. Use Add Time to Date to find an exact future date and time — perfect for deadlines and scheduling. Use Expression Mode for advanced users who want to type full time expressions. For calendar-based calculations, try our date calculator and age calculator.
86,400
Seconds in a Day
1,440
Minutes in a Day
24
Hours in a Day
60
Seconds per Minute
60
Minutes per Hour
604,800
Seconds in a Week
📐 How Time Addition Works
The calculator converts everything to seconds, adds/subtracts, then converts back:
Total seconds = d×86400 + h×3600 + m×60 + s
Then: days = total ÷ 86400
hours = remainder ÷ 3600
This sexagesimal (base-60) system handles all carry-overs automatically — 90 minutes becomes 1h 30m.
🔣 Expression Mode Examples
2h 30m + 1h 45m = 4h 15m
5h - 1h 20m = 3h 40m
1d 2h + 45m 30s = 1d 2h 45m 30s
90m + 250s = 1h 34m 10s
Supports any combination of d, h, m, s with + and − operators.
💼 Real-World Use Cases
Work hours: Total daily hours across multiple shifts
Project tracking: Sum time spent across tasks
Payroll: Calculate exact overtime hours
Travel planning: Add flight + layover + transfer time
Cooking/sports: Track multiple timers
Deadlines: Add duration to a start date
🌍 Time Zones & UTC
The world uses Coordinated Universal Time (UTC) as its primary standard. All time zones are offsets from UTC.
UTC−5 = Eastern US (EST)
UTC+0 = London (GMT)
UTC+5:30 = India (IST)
UTC+8 = China/Singapore
For date-based time differences, also use our date calculator.
Frequently Asked Questions
To add hours and minutes, enter the values in the Days/Hours/Minutes/Seconds fields in our time calculator and press Calculate. The tool handles carry-overs automatically — if your minutes total 90, it converts that to 1 hour 30 minutes. For example: 2h 45m + 1h 30m = 4h 15m.
There are 3,600 seconds in one hour (60 minutes × 60 seconds). One day has 86,400 seconds (24 × 3,600). One week has 604,800 seconds. Our time calculator shows the result of any time calculation in all units simultaneously — days, hours, minutes, and seconds.
Use the Add/Subtract mode and add a row for each work session. Enter the hours and minutes for each session, then click Calculate to get the total. For example: 3h 45m + 4h 30m + 2h 15m = 10h 30m total. This is perfect for freelancers, payroll calculations, and project tracking. You can also try our hours calculator for shift-specific calculations.
A time calculator works with durations — hours, minutes, seconds. It adds or subtracts time values. A date calculator works with calendar dates — finding how many days between two dates, or what date falls X days from now. Our "Add Time to Date" mode combines both. For pure date arithmetic, use our date calculator.
Expression mode lets you type a full time equation in one line. Use d for days, h for hours, m for minutes, s for seconds, with + and − between values. Example: "1d 2h 30m + 45m - 20s" — the calculator parses this, converts everything to seconds, performs the math, and shows the result in formatted time. It's ideal for engineers, developers, and analysts working with timestamps.
