TV
They are two separate channels with their own galleries, I presume. And since BBCWN has adverts in between programming and the like, BBCNC has to wait until they can join World. It's not really joining in "late" or "early" (technical cockups notwithstanding) but waiting for their cue to join. (e.g. of that: BBC Two was kept on standby for 5 minutes with a static "BBC Two" Bounce ident until it could join with BBC One to form "BBC Television News" and announce the Queen Mother's passing some years back). That's why some countdowns are shorter or longer and can air sans a clock to fill time.
Yes that was a bit of a cockup back then, and "not the BBC's finest hour" (if we adapt a phrase that applied to Independent Radio News at the time when radio stations didn't receive the obit alarm and just went unknowingly straight to the TOTH news). The announcement was made to BBC Two that they would be coming out of their programmes and joining BBC One so it seems they came out almost immediately, when BBC One weren't quite ready, and then spent an age announcing they would be joining BBC One soon, then waiting around and then announcing it again as BBC One still weren't ready, before, finally, at last, joining BBC One as "BBC Television News". They could have done it better, to have a few programme trails (obviously appropriate ones) on BBC Two and then going towards joining BBC One when they were almost ready, not having BBC Two hanging around for what was, indeed, probably only five minutes but seemed like an age. Or BBC Two could have come out of Steptoe and Son IIRC a little later than they did and just before the BBC News bulletin rather than immediately abandoning Steptoe the moment someone must have mentioned the Queen Mother's death to them and then waiting ages for an unready BBC One.
Why does the BBCNC TOTH countdown in the midnight does not sync with the BBCWN TOTH countdown during overnight simulcasts? As you can see in the opening sequence video below, the BBCWN countdown sequence is 2 seconds late:
https://www.youtube.com/watch?v=k8otovVZOac
https://www.youtube.com/watch?v=k8otovVZOac
They are two separate channels with their own galleries, I presume. And since BBCWN has adverts in between programming and the like, BBCNC has to wait until they can join World. It's not really joining in "late" or "early" (technical cockups notwithstanding) but waiting for their cue to join. (e.g. of that: BBC Two was kept on standby for 5 minutes with a static "BBC Two" Bounce ident until it could join with BBC One to form "BBC Television News" and announce the Queen Mother's passing some years back). That's why some countdowns are shorter or longer and can air sans a clock to fill time.
Yes that was a bit of a cockup back then, and "not the BBC's finest hour" (if we adapt a phrase that applied to Independent Radio News at the time when radio stations didn't receive the obit alarm and just went unknowingly straight to the TOTH news). The announcement was made to BBC Two that they would be coming out of their programmes and joining BBC One so it seems they came out almost immediately, when BBC One weren't quite ready, and then spent an age announcing they would be joining BBC One soon, then waiting around and then announcing it again as BBC One still weren't ready, before, finally, at last, joining BBC One as "BBC Television News". They could have done it better, to have a few programme trails (obviously appropriate ones) on BBC Two and then going towards joining BBC One when they were almost ready, not having BBC Two hanging around for what was, indeed, probably only five minutes but seemed like an age. Or BBC Two could have come out of Steptoe and Son IIRC a little later than they did and just before the BBC News bulletin rather than immediately abandoning Steptoe the moment someone must have mentioned the Queen Mother's death to them and then waiting ages for an unready BBC One.