What is the actual day of the last day of your period?

Julia • Short Princess

So I started my period Jan 2nd. I bled on 2nd and the 3rd and the 4th. I had no blood today. So did my period end yesterday or today? So on my app when I edit my period should it be red on the 2nd, 3rd and 4th? Or should it be red on the 2nd, 3rd, 4th, & 5th(today)? I’m so confused I don’t know how I forgot!