Task dates keep changing automatically

December 18, 2012 - 22:59 pm
14 comment(s)

Projectlibre seems a great tool, but I have the problem that when I add (sub-)tasks, for example a meeting, the dates change when I add other tasks. I'm really stuck in something that I suppose to be very basic, and probably I'm doing something very stupid, but I googled and searched the forums and it seems that I'm the onely one having this problem.

I thought it had to do with wrong constraints, but these constraints keep popping up automatically. I've seen the post http://ntrajkovski.wordpress.com/2011/04/12/constraints-and-deadline-in-ms-project/ but that doesn't help me very much.

Additionally: I find it hard to know when I can change a date and when not: sometimes it doesn't work at all....

Anyone an idea?


December 21, 2012 - 08:43 am

Hey there, if you send the project file to info@projectlibre.org we can take a look at it....  the dates of the parent may change based on the sub tasks.  You also may have a relationship between tasks such as SS or FF that would alter the dates of tasks....


Best regards,



April 19, 2013 - 18:12 pm

Hi there,

It seems I am also having similar problems to the use: Dotvan.

I have a project of my own and each new task I add in will not allow me to change its date. It seems that it is locked in by some constraint, however I have tried to get rid of all constraints, and even removed all other constraints from previous tasks...yet this seems to achieve nothing!

I am in urgent need of some help with this problem, can anyone help or offer a solution?

My project is not long, it only has a series of 5 or 6 tasks, each with an average of 5 sub-processes.

Someone please help soon!


thank you kindly.

April 29, 2013 - 15:46 pm

hi mikeyk

I would like to try helping you, but you give very limited information on what you have already in your plan and what you are adding and maybe most important how your  are adding new tasks.

in general  a new task not linked yet, should allow to either enter a duration and start date, (normaly start of project is defaulted as start date), or you may specify start and end date. (out of these 3 you can only specify 2      !)

have also a look at the calender you are using, does this allow for sufficient working hours?

also enter new tasks at the bottom and not in between other tasks, you can always move a task in the project later on.

that is what comes to mind just like that









May 8, 2013 - 08:38 am

Hello there...on the Gantt Chart spreadsheet there is an "Information" column next to the Task Name column.... if there is a constraint you will see an icon in that column.  It will look like a minuature calendar with a yellow dot in the calendar.....  If you do not see any constraints then it is your scheduling selections.....

Example:  If you have a task scheduled to fininsh As Late As Possible then the critical path algorithm will in fact schedule that as late as possible and will reset it there...

In reply to by mikeyk

March 3, 2014 - 01:56 am

Hello, I am new to projectlibre myself but I have just

discovered that it does not let you change the dates if you assign the task as completed %100

I dont know if it is the same with different %s but changing to 0% and then modifying dates and

durations solved my problems.


Hope this helps,


March 4, 2014 - 01:46 am

Hi Ziya,

Thanks for the note.... if a task is 100% complete based on project management theory it should not move. 





June 7, 2013 - 07:10 am

I, too, am dealing with automatic date changes. One thing I notice after reading the blog post linked in the initial question here, is that all my tasks default to the "start no later than" constraint. If I don't want that, I have to manually change it to ASAP and sometimes it simply switches back.

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The same thing is happening with duration, work time and start and stop time. They will switch to a different time just as soon as I think I've got them set. Currently most of my start and end dates are inaccurate and  one of my tasks has a big red x in the first column because it finishes after its deadline. That's because I can't set it to finish ON the deadline. (I also don't plan to be completing any tasks at 1:00 AM, the start time to which the task has defaulted.)

Image removed.

If I try to remove the constraint, my start date moves to June 1 and when I attempt to change that to June 6 it defaults to June 7. When I  go to Advanced the constraint is back.

The general project information does not seem to provide any clues.

Image removed.

Thanks for any help you can provide.

PS I pasted in snips of each of the problems mentioned, but it looks like you won't be able to see those. :(





June 7, 2013 - 09:33 am

Hi Kath,


I am sorry to hear of your issues.... the program does actually schedule correctly.  However, it does sound like your calendar is not set to default which is 8:00 - 5:00 otherwise it would not have your task scheduled at 1:00 AM to start...... One thing to keep in mind, if you take a task bar and move it graphically then a constraint is placed upon that task.  If you just enter task1 task2 task3 with 10 day durations and serially link the second task will start on working day 11 ..... If I move task 2 I insert a constraint on that task which is over riding the critical path methodology scheduling engine.  I hope that helps

June 13, 2013 - 07:11 am

Okay, I'm setting up a project from scratch and this time I started with the end date and have attempted to work backwards, insofar as that is possible. But it really is impossible to enter each task chronologically, as I'm figuring out how the dates fit together as I go. My task dates are STILL resetting themselves, and I keep having to go back and reset them, trying to remember what they were. For some reason they don't all reset themselves, but the ones that do are resetting to the final date of the project.

Isn't there a way to simply list the tasks and then put the dates in? This is very frustrating.

June 13, 2013 - 07:47 am

I just closed the program and then reopened it and all but three of the 19 tasks in my project have reset themselves to the last day of the project. Fortunately, I kept a snip of the way it was before, so I guess I'll just use that. This has taken hours. What am I missing?

July 14, 2015 - 15:03 pm

That is important but also a very tricky issue as we are coming out with a new version with new scheduling algorithms.  If we change things we could really break some critical items and then not have the focus to correct...



July 27, 2020 - 21:51 pm

I was having this issue and I went in and found a number of tasks were set "as late as possible" instead of "as soon as possible." I don't recall setting that, but as soon as I changed it, it worked for me!