# of months between two dates

Excellearner
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Dear experts,

I need a simple formula which can calculate the number of months between two dates. I have provided a formula which I picked it up from website and I wish to perfect it to:
consider the holiday if the later date is a holiday, then the formula should consider the day after the holiday and then include it as the month

The list of holidays is provided in sheet 'holidays'

Column F has the desired result.


Kindly help.

Thank you
--of-months-between-two-dates.xlsx
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Top Expert 2016

Commented:
Hi,

pls try

=DATEDIF(B9,C9-1,"m")+1

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Shouldn't line 5 be 13 Months

Regards

Author

Commented:
Rgonzo, yes it should be 13 and not 12.

Can you please help me understand the logic behind -1 inside the brackets and +1 outside the brackets.

Thank you
Top Expert 2016

Commented:
we take  may 1, 16 to June 2, 16
that makes
a difference of one month between  may 1, 16 to June 1, 16
plus 1 Equals 2
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Rob HensonFinance Analyst

Commented:
I was trying to take a look but having problems downloading the file.

DATEDIF doesn't take into account holidays.

NETWORKDAYS can take weekends and a list of holidays into account but that gives number of working days rather than months.

Thanks
Rob
Rob HensonFinance Analyst
Commented:
OK, got the file to open.

Formula in D9:

=IF(ISERROR(MATCH(C9,Holidays!A:A,0)),"",C9+1)

Then couple of options for column F:

=ROUNDUP(YEARFRAC(B9,IF(D9="",C9-1,D9-1),1)*12,0)

=DATEDIF(B9,IF(D9="",C9-1,D9-1),"m")+1

Also some questions:
1) What if Start Date is a holiday?
2) What if Finish Date is a holiday and Finish Date +1  is also a holiday?

Author

Commented:
Rob,

Here is the file.
--of-months-between-two-dates.xlsx
Top Expert 2016
Commented:
then

pls try
=DATEDIF(B9,D9-(D9-WORKDAY.INTL(D9,-1,MOD(WEEKDAY(D9)+1,7)+1,Holidays!$A$2:$A$20)),"m")+1

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--of-months-between-two-datesV1.xlsx

Author

Commented:
Rgonzo,

Can you please explain the logic in the formula. I could not understand it.

Thank you,
Rob HensonFinance Analyst

Commented:
I managed to get the file to download eventually before, hence the formulas which I posted.

Author

Commented:
Rob,

Also some questions:
 1) What if Start Date is a holiday? Very unlikely
 2) What if Finish Date is a holiday and Finish Date +1  is also a holiday? //Then move the date to the next working day but the Month count should still be in the previous month count or in the 1 month count (the floor value for the result)

Author

Commented:
Rob,

The values in column C and D are given I cannot amend those dates
Top Expert 2016

Commented:
this part
WORKDAY.INTL(D9,-1,MOD(WEEKDAY(D9)+1,7)+1,Holidays!$A$2:$A$20))

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calculates the first non holiday date before D9
this part
MOD(WEEKDAY(D9)+1,7)+1

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place the weekend after D9 to not affect the calculation of the non holiday date

Author

Commented:
Rob, a correction, sorry for my wrong comment

Values in Col. B and C are given and I cannot change them
Values in Col D are only shown for this illustration to convey my thought process. In the actual file this field would not exist.

Thank you

Author

Commented:
Rgonzo,

The number of months should be calculated based on values in col. b and C and column D would not exist in the actual file.

Kindly help.

Thank you
Top Expert 2016

Commented:
then my first formula would apply
Rob HensonFinance Analyst

Commented:
Am I right in thinking that you would still have to take into consideration the date in column C could be on the holiday list?
Top Expert 2016

Commented:
But the author says that the dates are in Col C and they are not adjusted for Holidays

Author

Commented:
Dates in col C are given and they can be coinciding with the list of the dates in the tab 'holidays'.

The idea is to get a formula to do the following:
1. check if the value in tab Examples, col C will coincide with the list in tab Holidays, Col A
2. Then the formula should increment the value in tab Examples, col C by one date
3. Further, the formula should check if the value arrived in step 2 above is working day or a weekend (Saturday or Sunday)
4. If the result of step 4 coincides with weekend, then the formula should increment it by 1 (if sunday)or 2 (if Saturday) to arrive at the next working day Monday.
5. if the result of Step 4 is Monday and a holiday (as per list), then it should increment by 1 day again to result in Tuesday.

Now suppose if as per the default calculation col. c less Col. B results in 2 months,
then by following step 2-5 should also result in 2 months and not 3 months.

Sorry if I have confused the forum and I hope I am clear with my request now.

Kindly help
Top Expert 2016

Commented:
Hi,

If it does not change the value of the result at the end, why does the formula have to know there is a weekend or a holiday?
Rob HensonFinance Analyst

Commented:
I agree with RGonzo, I think you are not comparing like with like, comparing whole months with individual days or small groups of days.

How can single or multiple holiday days have an impact on the result? For lapsed months the only way that holidays will have an impact is when you assign a whole month as a holiday.

Thanks
Rob

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