## Explanation

The RAND function generates a decimal number between zero and 1. So, you might get output like this from RAND() in three cells:

0.54739314

0.919767722

0.633760119

Dates in Excel are defined as simple numbers, where 1 = 1 day. This means you can simply divide 1 by the decimal value of time to get a value that corresponds to time as Excel sees it, for example:

1/12 = 12 hours = .5 days

1/6 = 6 hours = .25 days

1/8 = 8 hours = .333 days

This means we can use RAND() to generate a decimal value between 1 and 0, then round that number down with FLOOR to the nearest interval. FLOOR takes an argument called *significance* as the rounding multiple, and it recognizes time intervals expressed like this:

"0:10" - 10 minutes

"0:15" - 15 minutes

"0:30" - 30 minutes

"0:45" - 45 minutes

### Setting and upper and lower time

If you want to limit the hours used by RAND, you can use this general formula force RAND to output a number between an upper and lower value:

```
=RAND()*(upper-lower)+lower
```

Because Excel can recognize time values, you can get times between 8 AM and 12 PM, with a formula like this:

```
=RAND()*("12:00"-"8:00")+"8:00"
```

*Note: the formula above is general and will work with other numbers too, not just times.*