Day 4: 5:00 A.M.-6:00 A.M. - S4-E23
Corrected entry: When Mandy is talking to Tony in the apartment she says that two years ago he risked Michelle's life (in season 3). Three years seperated seasons 2 & 3 making this five years since season 2. However when Aaron is talking to the president in the next episode he mentions the attack on his life took place four years ago.
Correction: The season timeline is NOT wrong. Aaron said "four and a half years ago". The time difference between season 3 & 4 is 18 months, Series 3 takes place in september, placing Series 4 in march two years later.