Just a few minutes before the EMP blast, and after we saw that all communication lines are useless, Conlon (while searching for Paul Raines) speaks to the security on his radio.
When Habib gets on the bus near the beginning of the episode, the sun is just starting to set. But when Jack and and Paul are driving along, 10 minutes into the episode, it's complete night time out.
Tony said he ran CTU for two years. He took charge of CTU during Day 2 and was relieved of his command during Day 3. Three years passed between days 2 and 3, so Tony was actually in charge for three years.
Heller: I'd like you to stick around and assist Ms. Dessler.
Tony: I'm sorry, who?
Heller: Michelle Dessler. Do you know her?
Tony: I used to be married to her.