Figure out slot from given time [quick tip]

Here is an interesting scenario.

Let’s say you are looking at a time, like 9:42 AM and want to know which 15 minute slot it fits into. The answer is 9:30 – 9:45. But how would you get this answer thru Excel formulas?

Excel formula to find slot from time:

Assuming A1 contains the input time, here is one formula that tells you the time slot.

=TEXT(TIME(HOUR(A1),INT(MINUTE(A1)/15)*15,0),”hh:mm”)&” – “&TEXT(TIME(HOUR(A1),(INT(MINUTE(A1)/15)+1)*15,0),”hh:mm”)

Whoa!, that’s long. Let’s examine the inner workings of this beast.

Logic: We need to figure out both lower & upper boundaries of fifteen minute slot for time in A1. The lower boundary is quotient of A1/15 minutes multiplied by 15. For example, 09:42’s lower boundary is 09:30. The upper boundary is lower boundary + 15 minutes.

Implementation:

INT(MINUTE(A1)/15) * 15 portion: this part of the formula tells us the minutes. We extract the minute part of A1 (using MINUTE(A1)) and divide it with 15. We then take only the integer portion of this division and multiply that with 15 again. This gives us the minute portion of lower boundary of our time slot.

TIME(HOUR(A1), INT(..)*15, 0) portion: We then create a time value using the TIME formula by using the same hour as A1, minutes from lower boundary calculation using the INT(…)* 15  and 0 as seconds.

TEXT(TIME(…), “hh:mm”) portion: This will convert the time value to text formatted as hh:mm.

So far we have constructed the lower boundary of time slot. The upper boundary part of the formula is similar with one minor change. Go figure it out.

How to find 1 hour time slot?

Let’s say you want to find the time slot on hourly basis, then what?

Below formula does the job.

=HOUR(A1)&”:00 – ” & (HOUR(A1)+1) & “:00”

What if your time slots are not uniformly spaced?

The above approaches work fine as long as your time slots are uniformly spaced (ie 15 minutes, 1 hour, 4 hours or 8 hour apart). What if you have a unique set up? Something like this:

In that case you can use the range lookup method.

Related: read about pricing tier lookup too.

So there you go. For more information about working with date & time values in Excel, check out below material.

• Convert fractional time to proper time in Excel
• Find last day of any month with this simple trick
• 42 tips for Excel time travelers – Must read!!!
• Check if two dates are in same month
• More formulas & tutorials on Excel date & time

A challenge for you:

How would you write the 15 minute time slot formula? Can you figure out other ways to calculate it? Please share your formulas in the comments section. Your time starts now!