Last Day for Phase 1 Parses?

With Ulduar releasing on Jan 19th, but the update coming to servers on Jan 17th, we’re looking for clarification on when logs will begin to be considered phase 2: 1) as of the Jan 17th patch; or 2) on the 19th as of 3pm PST when Ulduar goes live?

We’re hoping it is the 19th to allow for guilds to submit their final chance to improve parses with the latest gear.

P1 ends with the reset time in each region.

Thank you for the quick reply and clarification.