# Calculate start date

##### New Member
Hi
I am trying to calculate the start date of the first operation based on the start date of the second operation. Typically this is always going to be 7 days (5 work days) before. I can do this easily by just deducting 7 from the second operations start date however I have a calendar lookup that checks if a particular day is a holiday which I use on other calculations for networkdays.

Is there an easy way to do this so the first operation is 7 days earlier but also taking into account any holidays identified so if a bank holiday for example it might start 8 days earlier to take into account the holiday

Regards
Stephen

#### jim may

##### Well-known Member
Are you aware of the native Workday function in Excel. One of its arguments is a range of Holiday dates assigned by you.
Hope this helps

##### New Member
Thanks but my understanding of workday function is its usually used to find an end date and you have to have start date and number of days as manditory fields with holiday being optional. Can I do start date -7 days and then look at the holidays to see if any fall in that range and push this new date back by that number of holidays.

2nd op starts on 11/11
1st op would be 7 days early 04/11
07/11 is a work shutdown
1st op needs to push back an extra day but because of weekend needs to be 01/11

#### Fluff

##### MrExcel MVP, Moderator
You can use it like
=WORKDAY(A2,-5,D8:D10)

where D8:D10 is your holiday dates