# Thread: How to calculate duration in days

1. Member
Join Date
Aug 2006
Posts
114

## How to calculate duration in days

I have recently created 2 new custom fields, that is, a date field (date1) and duration (duration1). I just want to calculate the difference in days between 'start' and dat1 in day. When I am trying to create a formula for duration1 of: start - date1 then I am getting an odd answer. Is there anyone who can give me some kind of a formula to calculate duration between 2 dates? Thanks.

2. Member
Join Date
Oct 2005
Posts
1,224

## Re: How to calculate duration in days

Incase you want the difference in calendar days, then you can simply use the DateDiff function and if you want the difference in Working Days, then you can use ProjDateDiff function. Hope this helps.

3. Member
Join Date
Aug 2006
Posts
114

## Re: How to calculate duration in days

Thank you, I tried to use the ProjDateDiff function but if I have got a different calendar than the project calendar then how can I make the distinction in the formula?

4. Member
Join Date
Oct 2005
Posts
1,224
You just need to put the name of the calendar between double quotes, like for example:
ProjDateDiff([Start],[Finish],"Six Days")

Hope this helps.

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•