Figure out slot from given time [quick tip]

Excel Howtos , Quick Tip - 15 comments

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.


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.

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!


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My name is Chandoo. Thanks for dropping by. My mission is to make you awesome in Excel & your work. I live in Wellington, New Zealand. When I am not F9ing my formulas, I cycle, cook or play lego with my kids. Know more about me.

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15 Responses to “Figure out slot from given time [quick tip]”

  1. MF says:

    How about using Floor and Ceiling?
    =TEXT(FLOOR(A1,TIME(,15,)),"HH:MM")& " - " & TEXT(CEILING(A1+(MOD(MINUTE(A1),15)=0)*(TIME(,1,)),TIME(,15,)),"HH:MM")

  2. esg says:

    continuing from MF:
    =TEXT(FLOOR(A1,1/96),"HH:MM")& " - " & TEXT(FLOOR(A1,1/96)+1/96,"HH:MM")
    (72 chars) although I would prefer to use a named range (one cell) called slot that contains the time per slot, in out case, 1/96
    =TEXT(FLOOR(A1,slot),"HH:MM")& " - " & TEXT(FLOOR(A1,slot)+slot,"HH:MM")
    This too, weighs in at 72 chars

  3. Stef@n says:

    as a basis for more creativity 😉

  4. K. Mann says:

    The mround function works fairly well for this problem...
    =TEXT(MROUND(A1,"0:15")-((MROUND(A1,"0:15")>A1)*("0:15")),"h:mm AM/PM")&" - "&TEXT(MROUND(A1,"0:15")+((MROUND(A1,"0:15")<A1)*("0:15")),"h:mm AM/PM")

  5. Haz says:

    =TEXT(MROUND(A1,"0:15"),"hh:mm")&" - "&TEXT(MROUND(A1,"0:15")+TIME(,15,),"hh:mm")

  6. SunnyKow says:

    My solution to question 2 would be using VLOOKUP.

  7. HSoomro says:


  8. Jude Shyju says:

    =TEXT(FLOOR(A1,0.25/24),"hh:mm")&" - "&TEXT(CEILING(A1,0.25/24),"hh:mm")

  9. Jason Morin says:


  10. Rajib says:

    Upper Bound: MROUND("Input Date","Increment")
    Lower Bound: MROUND("Input Date",2*"Increment")

    Increment in the format: "0:05" for 5 minutes

  11. JEFF says:


    0200 - 0600
    0600 - 1000
    1000 - 1400
    1400 - 1800
    1800 - 2200
    2200 - 0200


  12. yoav says:


    A1 is the current time.
    in B1 I wrote 00:15, or 01:00...

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