Mariana Holostenco December 04, 2021

How many hours between two times

Calculate

How many hours between two dates (times included)

Calculate

The only thing to keep in mind when we want to know the answer to this question is the type of year we are we are referring to.

The Solar year has 365 days, 5 hours, 48 minutes, and 46 seconds, while the Calendar year has the following:

- For three years in a row, there are 365 days; this is the so-called Regular (or Normal) year.
- In the fourth year, there are 366 days because the time differences from the previous three years are added; this is called the Leap year.

Because each day has 24 hours (day+night included) and a Regular year has 365 days, we just multiply the numbers. The result is 8760 hours.

24 hours/day x 365 days/year = **8760 hours**

As we have seen, a Leap year has 366 days. So, if we multiply this by 24 hours a day, the result is 8784 hours.

24 hours/day x 366 days/year = **8784 hours**

When it comes to working hours, things are not so simple.

We can consider the fact that there are 52 weeks in a year and that we have 40 hours per week. Thus, we get
2080 work hours in a year.

52 weeks/year x 40 work hours/week = **2080 work hours/year**

The U.S. Office of Personnel Management (OPM) assumes 2087 hours per year when calculating hourly pay rates. This number has been reached because it has been shown that for 28 years, we have years with different numbers of working days.

Four of them have 262 working days, 17 years have 261 each, and seven years have 260 working days each.

If we multiply the total number of working days in the 28 years by 8 working hours per day, we get the total number of working hours in the 28 years (in this case, 58,440 hours).

Finally, to find the average number of hours worked each year among the 28, we divide the total number of hours obtained earlier by 28 years. We will get 2087.142, rounded to 2087 working hours for one year.

No. of years A |
No. of workdays/year B |
No. of working hours/day C |
Working hours/year D = B x C |
Working hours/no. of years E = D x A |
---|---|---|---|---|

4 | 262 | 8 | 2096 | 8384 |

17 | 261 | 8 | 2088 | 35496 |

7 | 260 | 8 | 2080 | 14560 |

Total working hours in 28 years | 58440 | |||

Average hours worked each year out of the 28 | 2087 |

This number represents the total number of working hours in a year, without taking into account vacations or paid leave.

If we want to know the exact number of working hours for a certain year, out of the total working hours, we must subtract the following, if applicable:

- Vacation leave
- Sick leave
- Personal leave
- Family sick leave
- Medical leave
- Funeral/Bereavement leave
- Jury duty or witness duty
- Holidays

Depending on the state, the school year (or academic year) usually has a minimum number of instructional days
between 160 and 180. Also, regarding the minimum number of hours, Education law §3604(7) and Commissioner’s
Regulations §175.5 require districts
to provide both 180 days of session and a minimum of

**450 instructional hours for half-day
kindergarten, 900
instructional hours for full-day kindergarten through grade 6, or
990 hours of instruction for grades 7-12.**

Sometimes, a certain number of days per year and hours per year (sometimes even minutes) are established. However, in some states, there is the possibility of fulfilling only one of these two requirements. Note that this number of hours does not include breaks, weekends, or holidays.

Here are some differences between states in terms of the number of hours and related requirements:

- Kentucky – 1062 hours, 6 hours minimum per school day
- Louisiana – 1062 hours; 63,720 minutes minimum per school year
- Maine – 437.5 hours for kindergarten (min 2.5 hours/day); 875 hours for grades 1-12 (min 5 hours/day)
- North Carolina – 1,025 hours
- North Dakota – half-day kindergarten: 481.25 hours; grades K-5: 962.5 hours; grades 6-12: 1,050 hours

Not all months of the year have the same number of days. Therefore, the number of hours will vary from one
month
to another.

In a year, we have seven months with 31 days, four months with 30 days, and the month of February, which
generally has 28 days (though once every four years, it has 29 days).
Knowing this information, we have to multiply the number of hours in a day (24) by the number of days in that
month.

The months with 31 days—namely, January, March, May, July, August, October, and December—have 744 hours.

24 hours/day x 31 days/month = **744 hours**

The months with 30 days—namely, April, June, September, and November—have 720 hours.

24 hours/day x 30 days/month = **720 hours**

For three years in a row, the year has 365 days. These are the Regular years when February has 28 days, which equals 672 hours.

24 hours/day x 28 days/month = **672 hours**

Once every four years, in the Leap year, February has 29 days, so that it will have 696 hours in that year.

24 hours/day x 29 days/month = **696 hours**

Simple reasoning tells us that if there are four weeks each month and 40 hours of work each week, we have 160
hours of work each month.

But we must consider that the months do not all have the same number of days.

2021 | 2022 | ||||
---|---|---|---|---|---|

Month | Total days | Work days | Work hours | Work days | Work hours |

January | 31 | 21 | 168 | 21 | 168 |

February | 28 | 20 | 160 | 20 | 160 |

March | 31 | 23 | 184 | 23 | 184 |

April |
30 | 22 | 176 | 21 | 168 |

May | 31 | 21 | 168 | 21 | 168 |

June | 30 | 22 | 176 | 22 | 176 |

July |
31 | 22 | 176 | 21 | 168 |

August |
31 | 22 | 176 | 23 | 184 |

September | 30 | 22 | 176 | 22 | 176 |

October | 31 | 21 | 168 | 21 | 168 |

November | 30 | 22 | 176 | 22 | 176 |

December |
31 | 23 | 184 | 22 | 176 |

Total |
365 | 261 | 2088 | 260 | 2080 |

As we can see in the table above, the number of working days in the same month may differ even from one year to another. This happens because the weekends of a month are not the same every time.

**Note:** The above calculations are made taking into account only weekends and weekdays; they
do not include
holidays.

Regarding the week, we have to differentiate between the calendar week and the workweek. Therefore, in the first situation, we will calculate all the hours included in the seven days and only the hours dedicated to work in the second.

Regardless of whether we consider that it starts on Sunday or Monday, the calendar week has 7 days, which means it has 168 hours.

24 hours/day x 7 days/week = **168 hours**

When we refer to the working week, we usually consider 5 days. Specifically, from Monday to Friday inclusive, there are 8 hours a day.

8 hours/day x 5 days/week = 40 hours

We must keep in mind that, according to FLSA, the minimum hours to be worked for the minimum wage are 40 per week. Therefore, any hour worked over this number will have to be paid extra.

A calendar day has 24 hours. That means counting from one midnight to the following midnight. However, depending on the context, when we say "day," we might be referring only to the hours when there is light outside.

It is common to use “daytime” and “nighttime.” This establishes that it is not about the entire 24-hour period but only a specific part.

We generally say “daytime” when referring to the time interval in which the outside is light. Theoretically,
this time includes the hours from sunrise to sunset.

Similarly, we say “nighttime” for the time between the last ray of sunshine and the first ray of the next day.
However, there is no exact number of hours for these expressions because the number of hours in the daytime
and
nighttime changes during the year depending on the rotation of the earth around the sun.

According to legislation, the regular working hours are eight per day. However, often, this does not mean that people cannot work more than eight hours a day. Instead, it means that those extra hours will be considered overtime and be paid as such.

There are two numbering systems for the 24 hours: one that uses the numbering of hours from 1 to 24, and another that divides the 24 hours into equal parts and numbers the hours from 1 to 12, with the mention of a.m. or p.m.

As the name suggests, in this system, the hours are numbered from 1 to 24. In fact, the hour 24:00 can also be written as 00:00 and is considered both the end of the day that has passed and the start of the day that is beginning.

Sometimes, for a more apparent distinction of this hour, you can use 24:00 to mark the end of a day and 00:00 to the beginning. For example:

- the fact that the train will arrive at the station on Wednesday at 24:00 means that it will arrive there at the last moment of Wednesday, on the night between Wednesday and Thursday;
- and the fact that the train will leave the station on Wednesday at 00:00 means that it will go on the first moment of Wednesday, on the night between Tuesday and Wednesday.

24 hours | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|

1:00 | 2:00 | 3:00 | 4:00 | 5:00 | 6:00 | 7:00 | 8:00 | 9:00 | 10:00 | 11:00 | 12:00 |

13:00 | 14:00 | 15:00 | 16:00 | 17:00 | 18:00 | 19:00 | 20:00 | 21:00 | 22:00 | 23:00 | 0:00 |

In this numbering system, the 24 hours are divided into two periods. One of them corresponds to the morning period, which begins at midnight and ends at noon, and the afternoon period, which begins at midday and ends at midnight.

The hours are numbered from 1 to 12 in each of the two periods with the mention of the period to which the hour belongs. For example: 03:00 a.m. (antemeridian or before midday) or 03:00 p.m. (post meridian or after midday)

12 hours | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|

1:00 AM | 2:00 AM | 3:00 AM | 4:00 AM | 5:00 AM | 6:00 AM | 7:00 AM | 8:00 AM | 9:00 AM | 10:00 AM | 11:00 AM | 12:00 PM |

1:00 PM | 2:00 PM | 3:00 PM | 4:00 PM | 5:00 PM | 6:00 PM | 7:00 PM | 8:00 PM | 9:00 PM | 10:00 PM | 11:00 PM | 12:00 AM |

There is such a thing! It even happens every day—more precisely, twice a day!

Its duration fluctuates from one situation to another. No two are alike :)

- Morning rush hour is the time interval when the biggest traffic congestion is formed exactly when you are in a hurry to get to the office, It can happen anytime starting at 6:00 and can last until 10:00. The peak is between 7:30 and 8:30.
- Afternoon rush hour happens between 03:00 and 07:30 p.m. Maximum congestion in traffic is between 05:00 and 06:00 p.m.