I agree but when you have mixed crews(reserves, bunkies and dual crews) from different id's and domiciles having one reference time solves a lot of problems. Have you ever gone back to the hotel to pick-up a crew-member?

Company recently had a problem in AMS where the bunkie had a layover at a different hotel - he was supposed to walk over to main crew hotel to join the crew. We had delayed flights because nobody told them and the main crew thought he would join at the airport. Company changed it to have van pick up at both hotels. Guess what, they would determine their own pickup time and nobody informed the main crew. Main crew would leave them at the hotel. The company blamed the pilots for this snafu. Yes, FSAP's were written.

The point is, it's far easier for the company to publish a pickup time and pickup location in the same place on the id's for all to see.