To insert the current date and time into a form (or report) you should be in form design mode (or report view):
Select Date and Time from the Insert menu.
The mouse pointer turns to a cross. Place this where you want the date and time field to appear and click once on your mouse.
The field will be inserted at the chosen place.
In forms, click on the Browse button to switch to browse mode. Each form will now contain the current date and time.
In reports, click on Print Preview. Each page will display the date and time. Note that the date and time field is repeated every time the section where it was inserted is repeated.
Note that the date and time field is live and so will alter as the date and time change.