Period Starts At Night If Your Period Starts At Night, Do You Count That Date Or The Next Morning?

If your period starts at night, do you count that date or the next morning? - period starts at night

For example, if you do not start today or tonight 7.28.08, but if I sleep, "still has today's date, or 29? Besides, I have never had a bleed, but recognize the tan and pink to dark red . During my tenure as formal as a starting point? I was by the discharge is, therefore, rose-red light on it. Thank you!