Convert Days (d) to Hours (hr) | d in hr

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Let's convert Days (d) to Hours (hr)

This quick and easy calculator will convert Days (d) to Hours (hr) and show formula, brief history on the units and quick maths for the conversion.

Enter Days to convert to Hours


Quick Reference for Converting Days to Hours

Formula
hr = d x 24
Quick Rough Maths
To get the Hours, multiply the number of Days by 24.0
Days (d) in 1 Hour
There are 0.04 Days in 1 Hour
Hours (hr) in 1 Day
There are 24 Hours in 1 Day

Unit Information

Day
/deɪ/
Symbol: d
Unit System: SI

What is the Day?

The day is a unit of time and is an SI-derived unit with the symbol d.

On Earth, it is defined as 86,400 seconds and is approximately the time it takes for the earth to complete a full rotation around its axis. In the earlier days, this was measured by waiting for a cast shadow to match a template drawn from the previous day's shadow.

There are 365 days in a year and, on average, 30.42 days in a month.

The unit day has many different variants; depending on what is used to measure the Earth's rotation. In a sidereal day (a rotation with respect to a distant star or constellation, not the sun), there is actually 4 minutes less than 24 hours in a cycle.

Hour
/ˈaʊə/
Symbol: hr
Unit System: SI

What is the Hour?

The hour is a unit of time and is a multiple of an SI base unit with the symbol hr.

There are 60 seconds in a minute and 60 minutes in an hour. Consequently, there are 3600 seconds in an hour.

In a mean solar day, there are 24 hours.

Originally in the Middle East, the hour was defined as 1/12 of the day or night time. However, seasonal factors clearly affected all of these definitions and an average is used today to normalise and allow calculations.


Conversion Tables for Days (d) to Hours (hr)