Hello, i'm new in this community, my ask is the next

I'm have two forms, in one the users introduce a date with the class QDateEdit then, the user's click on a push button and he goes to a second form, when the user do click in the first from, the date store pass to second form how to qstring, i'm know transform the control qdate to qstring, but, i don't know how pass the variable that contain the date (qstring) to the second form, how i did this?