Stretching question

Hi Guys,

I just wanted to ask what is more beneficial or if there is any difference in the amount of time you hold each stretch?

this is my current routine:

Set 1:
Up, Down, Left, Right, Straight out stretches holding for 30seconds each

Set 2:

U,D,L,R,S - 1minute holds each

Set 3:

U,D,L,R,S - 30 seconds each

Set 4:
1minute 360 degree stretch (i think this is a “rotary crank”)

Set 5:
Up, Down, Diagonal stretch upwards and downards both left and right sides - 30 seconds

Set 6: finish off with 2x30 second 360degree stretch

total time: 15minutes

I just wanted to know if its better to do longer stretches -1minute+ or more sets of 30 second stretches?

Thanks