I created a task in MS Project 2010 which starts on 14-Oct-2011 and has a duration of one day.

Project automatically sets the Finish Date to 17-Oct-2011 (because the 15th and 16th are weekend non-working days).

However my task will really finish on the same day i.e. 14-Oct-2011, but when I set the Finish Date to 14-Oct-2011 MS Project shows the task as having a duration of 0.88 days which is wrong:

enter image description here Why is this and is there a way around it?


Had a fiddle around with the Default start/end time values in File -> Options -> Schedule page. I changed from 0800/1700 to 0900/1800.

I then changed the project's Working Time (Project -> Working Time) [Default] working time for the week from:

Monday to Friday: 08:00 to 12:00 and 13:00 to 17:00


Monday to Friday: 09:00 to 17:00

I'm not sure why this works because the number of working hours (8) per working day hasn't actually changed.

  • It works now because you have the same start time in the default working time and on task: that is 09:00. That was what I explained you bellow when I recommended you to use 08:00 :) Of course you can use any start time as long it is the same...
    – tiberiug
    Mar 19, 2013 at 14:02

2 Answers 2


In MS Project's configuration, when does your day start and end? 0.875 days is 21 hours.

Try making the task "8 hours" long instead of "1 day" long. If a "1 day" task starts at 9:00am, it finishes at 9:00am the next working day.

  • You are confusing people with bad answers. 0.875 days does not necessary mean 21 hours. It depends on what settings and what working calendar he has and you do not have access to this information.
    – tiberiug
    Mar 19, 2013 at 14:10
  • @tiberiug: I don't have Project available at the moment. Just so I'm clear, do you mean that if I have Project set up for an 8-hour work day that 0.875 days is actually 7 hours? Mar 19, 2013 at 22:24
  • 1
    Exactly. The value that you set for "Hours per day" will be used for the 1 day duration. And by default it is set to 8 hours and not 24 hours.
    – tiberiug
    Mar 20, 2013 at 13:14

It behaves like that because when you said 14-Oct-2011 for the start date you did not tell MS project the time. You should have set also the start time the same as the day start time from the Working Time that is 08:00. More than probably the start hour was 09:00 because of the Subtask 1 predecessor that also started at 09:00.

I do not know why Subtask 1 started at 09:00 because I do not have enough information from that screen shot.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.