If I open a file on iPad is there a way to not have the date/time change from what it was before opening?

Hi HoHop,

The option to keep the date and time from updating after opening a file isn't currently an option.

If you'd like to leave feedback for Apple, you can do so here: Product Feedback

Best regards.

The date/time will not change if there’s absolutely no modification to the original file.

Whether the original file is modified may well be beyond your control.