Earliest Bag drop time

Good evening all,
I think I’ve made a faux pas....I’ve arranged for my taxi to Heathrow early afternoon to allow for bad traffic on M1 and M25 which means I will be there by half 4 of traffic is ok.
I completely forgot about the 3 hours before flight checkin /bag drop, we are flying on VS 206 at 21:00 so what will be the earliest time we can bag drop for our flight
Many Thanks
Andy
I think I’ve made a faux pas....I’ve arranged for my taxi to Heathrow early afternoon to allow for bad traffic on M1 and M25 which means I will be there by half 4 of traffic is ok.
I completely forgot about the 3 hours before flight checkin /bag drop, we are flying on VS 206 at 21:00 so what will be the earliest time we can bag drop for our flight
Many Thanks
Andy