It's the 8th and time zone goes with time at departure in local time.

Note that 21:00 on 8th will not post until after membership year and possibly after automatic reset which is usually two days later.

However, call to BAEC will get TPs assigned to correct year and status renewed if that is an issue.

Also, don't assume that old year TPs will count to new year if you don't need them in old year. I have seen them zeroed out before now.