Thank you guys for your comments ^^
@Sarthak: Oh I see but in maths I remember using [XX;XX] and not [XX-XX] even if it's more familiar , thank you I thought it was a huuuuuge mistake
@jacee: Oh I don't know I'm using google form to make it easy but maybe it's not very good on mobile
@Karpeles: Crazy cat lady here =^_^=
@Katrimans: haha yeah I think I'll try to limit the date of birth a little bit
edit: It's set from 1920 to 2006 now! ^^