### Add hours to a time

You can add (or subtract) a number of hours from a time using fractions.
Dates are represented as sequential whole numbers so 1 hour is equivalent to the fraction (1/24).
Times are represented as fractions based on there being 24 hours in a day.
1 Hour is 1/24 = 0.04166
1 Minute is 1/(24*60) = 1/1440
1 Second is 1/(24*60*60) = 1/86400

Cell "A1" displays the current date. Custom format "dddd dd mmmm yyyy".
Cell "A2" displays the current date and time. Custom format "dddd dd mmmm yyyy hh:mm:ss".
Cell "A3" displays the current time plus 6 hours.
Cell "A4" displays the current time plus 6 hours using the TIME function to return the correct decimal.
Cell "A5" displays the current time plus 8 hours and 15 minutes.
Cell "A6" displays the current time plus 8 hours and 15 minutes using the TIME function to return the correct decimal.
Cell "A7" displays the current time plus 13 hours, 25 minutes and 45 seconds.
Cell "A8" displays the current time plus 13 hours, 25 minutes and 45 seconds using the TIME function to return the correct decimal.
All these cells have been formatted with the custom number format "dddd, dd mmmm, yyyy hh:mm AM/PM".

 A 1 =TODAY() = Wednesday 11 August 2021 2 =NOW() = Wednesday 11 August 2021 16:06:50 3 =A2+(6*(1/24)) = Wednesday, 11 August, 2021 10:06 PM 4 =A2+TIME(6,0,0) = Wednesday, 11 August, 2021 10:06 PM 5 =A2+(8/24)+(15/1440) = Thursday, 12 August, 2021 12:21 AM 6 =A2+TIME(8,15,0) = Thursday, 12 August, 2021 12:21 AM 7 =A2+(13/24)+(25/1440)+(45/86400) = Thursday, 12 August, 2021 05:32 AM 8 =A2+TIME(13,25,45) = Thursday, 12 August, 2021 05:32 AM

#### Built-in Functions

NOW - The serial number of the current system date and time.
TIME - The time as a decimal given an hour, minute, second.
TODAY - The serial number representing today's date.