For me, there are two opposing schools of thought.
(Caveat: the following applies to “one off” tasks that live on their own; if you have process projects with workflows and dependencies, then every task will need a due date for sure.)
One is the approach that you should always set a due date for every task. This is the “nothing gets done without a deadline” camp. Here’s one explanation of this philosophy: https://www.planplusonline.com/if-it-wasnt-for-deadlines-nothing-would-get-done/
The other approach (which is where I throw my support) is the idea that you should only assign a due date if a task absolutely has to be done by a certain date, otherwise leave it blank. Here’s an explanation of this approach which I’ve written about elsewhere:
I advocate assigning a due date to a task only when it absolutely has to be done on or by a certain date . If you have a meeting scheduled for next Thursday morning, and you have a report to prepare for the meeting, then it would be appropriate to assign a due date of next Wednesday for that item, because it has to be done by then.
But you’ll find that the majority of tasks live in the realm of “I need to get that done currently” or “now” or “as soon as I can”, or in the realm of “I’m not going to be doing that just now”. For these items, assigning a due date is not necessary and in fact can be counterproductive for several reasons:
Logistically: The odds are that you will not get everything done that you planned to do on a given day. If you have a due date assigned to a number of items that are not completed on that date, you will end up wasting precious time adjusting and tweaking due dates on these items.
Psychologically: If you do not get everything done that you marked as due for that day, it will be obvious as the due date stares you in the face, and you’ll tend to beat yourself up for it: “Darn, I planned to do those six things today and I didn’t get them done!”
This approach argues that priorities change day to day, and that rather than assigning dates to all tasks, you should re-evaluate and re-order your task list first thing each morning to reflect the current priorities at that time.
You might want to discuss both of these approaches with your team, decide on one of them, try it out for some agreed-on time frame, and see how it works. Then try the other approach for a time, and see which one works best overall.
The only “catch” I’ll add is that how an individual mentally interacts with due dates is a pretty personal thing and varies from brain to brain, so to speak - some people will respond better to one approach while others’ brains work best with the other philosophy. But you’re likely going to struggle as a team if some members use one approach and others use the other, so you’ll probably need to choose one way as a team and stick with it.