Funnily enough was just running through this when testing something else Here are the settings I used in window manager:
Date CheckBox = True
DateTime Range Operator - leave this blank
DateTime Range Attribute = Creation Date
Date CheckBox Checked = False
DateTime Display Type = DateOnly
ShortDate Format - set as required mine was set to False
What will happen is that when you open the window today's date should be displayed but with the checkbox next to the date not selected. Therefore if nothing is changed on the date field a NULL will be recorded for the date. If you check the box next to the date then today's date will be stored in the field. If you want to override the date then check the box and click the calendar to pick your required date.
I hope this is what you were hoping for.
Thanks for you quick answer.
However, when starting to check out your suggested solution, I noticed that the behaviour I'm looking for actually is the default behaviour . This without setting the Range attribute or Date Checkbox.
It seems as my window/field had some baggage I wasn't aware of.
Ah yes good point well made! I had been changing the various settings around for my test so missed that. Glad you found the answer
The difference between my settings and the default setting is that this allows NULLs in the field should you require to give users this option.