Hi Jeffrey. Need more info than this. Possibly some screen shots of what you're trying to do?

The tech's select there names in the combo boxes, click E button next to their name to open an event form that is populated with the date, and their name. The date is based on the text box on the main form with the date displayed. I don't want the date textbox on the main form to change at midnight but at 6am when the next day crew starts. Once they fill out and save the event it is displayed in the sub-report on the bottom. Thanks

Why not set up functions to work by shifts? or provide date n time at start of shift and dont update on close of shift?
What do you think?

Then you need to set your own date value.  You can't use the date from your computer's internal clock, i.e. can't use Now() or Date().  You need to set your date value to be the previous day's date if the current time is between 12am and 5:59am.  This can be done with just an expression, with no VBA.  Set your date textbox's value (or default value) to be:

=IIf(Hour(Time())>=0 And Hour(Time())<6,Date()-1,Date())

But this only works once: the moment you open the form.  If your form stays open past 12am or past 6am, the above expression won't run again and thus won't update your date.  So somewhere on your form you need this expression to run again *when it needs to*, such as with a Refresh or Requery statement in VBA.  It's up to you when and how to refresh it: with a form's Timer event, a button's Click event, a control's AfterUpdate event, etc.

I tried Kevin's approach. If Nights was selected and E button was clicked then... but I ran into data mismatch, not sure why at this point.

Hi Jeffrey, my formula evaluates to a date value, so make sure whatever variable or field you put my formula in uses the data type of a date also (i.e. not string, not numeral, but date) to avoid data mismatch error.