>>3151022But that scenario wouldn't make sense from what we're shown in the episode either.
Alarms don't start to go off until Kaworu actually takes Unit 02 and starts his decent, he's been in NERV HQ for some time.
And we see Shinji is not only in the HQ, but in Unit 01 AND his pilot suit already just a few moments afterwards.
So Shinji must have already been in the vicinity, or else they wouldn't have bothered to take the time in getting him in his suit.
Given the fact that Misato and co. were all coincidentally there, Kaworu obviously chose now of all times to strike instead of late night or early morning where no one would be able to stop him from getting to Dogma. He intentionally wanted everyone there.
As for the timestamp, we're given some hints throughout the episode on what the frame could be but no specifics. Though I'm sure some databook out there has listed an hour.
The timeline of Kaworu's appearance to death occurs a span of around three days, which a lot of people seem to forget.
We first see him at sunset.
The next scene of him is the next day, probably near mid-afternoon which is when sync testing usually takes place. Shinji and Kaworu go showering and go back to his place in the early evening.
Another day passes as Kaworu meets with SEELE in the morning. After this we see several scenes of Misato and Gendo as well. I would say it makes sense for the attack to occur around mid-day. And if we are to assume it was about 1-2 hours then it makes sense for it to already be nighttime when we see Shinji at the beach, obviously having been sitting there for some time as well.