Enter the time values & days into the given calculator to figure out the sum or difference.

(**Note:** Blank inputs are considered **"0"**)

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The calculator will help you schedule your plans by adding or subtracting the custom time inputs from a start time & date.

(**Note:** Blank inputs are considered **"0"**)

The following calculator lets you input times as expressions and adds or subtracts according to the operator you select.

(Valid Expression: 4d+7h-2m+1s)

In straightforward terms, this time calculator lets you effectively manage clock time for different events using dynamic customization features that include:

- Add or subtract two clock times
- Add and subtract time concerning a starting date and time

To start, follow the guide mentioned as under:

- Enter the values given in start time & end time fields
- Select if you want to Add or Subtract times
- Click Calculate
- The time calculator will give you accurate calculations for the clock times according to the arithmetic operation you selected

The best and most straightforward way to calculate times is by time calculator. But if your goal comes up with manual calculations, then the following examples will certainly help you.

It is preferred to add time by converting all the units in terms of seconds. It will make the calculations quite simple.

**4:15:10 & 3:29:03**

**Step # 01**

1 Hour = 60 * 60 sec = 3600 sec

1 Minute = 60 sec

**Step # 03**

Convert second time in seconds:

**3:29:03**

= (3*60*60 sec)+(29*60 sec)+(03 sec)

= (10800 sec)+(1740 sec)(03 sec)

**= 12543 sec**

**Step # 05**

**Calculate Days**

1 day = 24 hours

1 day = 24×60×60 sec

1 day = 86400 sec

As we are having a total of **20,653**, so we have:

Days = 20,653/86400

Days = 0

**Step # 02**

Convert first time in seconds:

**4:15:10**

= (4*60*60 sec)+(15*60 sec)+(10 sec)

= 7200sec+900sec+10sec

**= 8110 sec**

**Step # 04**

**Add Seconds**

= (8110 + 12543) sec

**= 20,653 sec**

**Step # 06**

**Calculate Hours**

Hours = 20,653/3600

Hours = 5.736

**Step # 07**

**Calculate Minutes**

Minutes = 20,653/60

Minutes = 344.2

To subtract time, you will again have to follow the same way i.e. keeping the units in sec

**Remember that:**

- To subtract times, the first time must be greater than the second time

**6:40:17 & 1:03:21**

**Step # 01**

Again we have:

1 Minute = 60 sec

1 Hour = 60 * 60 sec = 3600 sec

**Step # 03**

Convert second time in seconds:

1:03:21

= (1*60*60 sec)+(03*60 sec)+(21 sec)

=(3600 sec)+(180 sec)(21 sec)

**= 3801 sec**

**Step # 05**

**Calculate Days**

1 day = 24 hours

1 day = 24×60×60 sec

1 day = 86400 sec

As we have a total of **20,216**, so we have:

Days = 20,216/86400

Days = 0

**Step # 02**

Convert first time in seconds:

**6:40:17**

=(6*60*60 sec)+(40*60 sec)+(17 sec)

= 21,600 sec + 2400 sec + 17 sec

**= 24,017 sec**

**Step # 04**

**Subtract Seconds**

**= (24,017 - 3801) sec**

**= 20,216 sec**

**Step # 06**

**Calculate Hours**

Hours = 20,216/3600

Hours = 5.615

**Step # 07**

**Calculate Minutes**

Minutes = 20,216/60

Minutes = 336.0

Unit | Definition |

millennium | 1,000 years |

century | 100 years |

decade | 10 years |

year(average) | 365.242 days or 12 months |

common year | 365 days or 12 months |

leap year | 366 days or 12 months |

quarter | 3 months |

month | 28-31 days Jan., Mar., May, Jul., Aug. Oct., Dec.—31 days Apr., Jun., Sep., Nov.—30 days. Feb.—28 days for a common year and 29 days for a leap year |

week | 7 days |

day | 24 hours or 1,440 minutes or 86,400 sec |

hour | 60 minutes or 3,600 sec |

minute | 60 sec |

second | base unit |

millisecond | 10^{-3} second |

microsecond | 10^{-6} second |

nanosecond | 10^{-9} second |

picosecond | 10^{-12} second |