To get the difference between two dates, simply subtract one from the other:
`Date2 - Date1`

. If the number of hours won’t exceed 23 and the number of
minutes or seconds won’t exceed 59, you can use the HOUR, MINUTE and SECOND
formula functions to do the conversion.

`HOUR(Date2 - Date1)`

returns the number of hours there are between the two
dates.

`MINUTE(Date2 - Date1)`

returns the number of minutes there are between the two
dates.

`SECOND(Date2 - Date1)`

returns the number of seconds there are between the two
dates.

These functions are designed to be used together, meaning that the the HOUR
function won’t ever return a number greater than 23 and the SECOND and MINUTE
functions won’t ever return a number greater than 59. For instance, if four
hours, three minutes and two seconds have elapsed between two dates,
`HOUR(Date2- Date1)`

returns 4, `MINUTE(Date2 - Date1)`

returns 3 and
`SECOND(Date2 - Date1)`

returns 2.

If you’re just interested in the number of seconds that have elapsed between the
two dates, though, the number you’re looking for is 14,584 seconds. (Each minute
has 60 seconds and every hour has 60 minutes, meaning that 14,584 equals
`4 * 60 * 60 + 3 * 60 + 4`

).

Similarly, if you’re interested in the number of minutes that have elapsed
between two dates, the number you’re looking for is 243 minutes. (Each hour has
60 minutes, meaning that 243 equals `4 * 60 + 3`

).

In Calcapp, as in spreadsheets, a date is a so-called sequential serial number. For the purposes of this discussion, we can ignore how days are represented and just be content to note that the sequential serial number 1 equals one day or 24 hours. This means that the number 1/24 represents one hour, 1/24/60 represents one minute and 1/24/60/60 represents one second.

That means that you need to use these formulas if you can’t use the HOUR, MINUTE and SECOND functions:

`(Date2 - Date1) * 24`

returns the number of hours there are between two dates.

`(Date2 - Date1) * 60 * 24`

returns the number of minutes there are between two
dates.

`(Date2 - Date1) * 60 * 60 * 24`

returns the number of seconds there are between
two dates.

(If you’re interested in having apps that perform as speedily as possible, you
may be tempted to write `60 * 60 * 24`

as `86400`

. That won’t actually improve
performance, as Calcapp automatically does this optimization before your app is
run. This is known as constant folding. By typing ```
60 * 60 *
24
```

instead of `86400`

, your formulas will be easier to read.)

*Do you want to share a tip with other Calcapp users through this blog? Let us
know!*