Timeline - Season 4 (RDM)

He That Believeth In Me

The episode continues directly from "Crossroads, Part II". More than two months have passed since Kara Thrace's believed death in "Maelstrom".

The Cylons inflict large damage on the civilian Fleet, but retreat after noticing that the Final Five have been activated.
Kara Thrace returns, but is met with disbelief and distrust. Determined to lead the Colonials to Earth, she confronts Roslin with a weapon.
A cult has arisen around Gaius Baltar.

Six of One

The episode continues directly from the previous one.

Tory Foster sleeps with Baltar in order to gain access to his knowledge about the Cylons and the Final Five.
One faction of the Cylons lobotomizes the Raiders for refusing to fight against the Final Five. In retaliation, another factions, one of them led by Natalie, removes the Centurions' inhibitors who in turn kill the first faction.
Kara Thrace is given command of the Demetrius to search for Earth.

The Ties That Bind

The first scene shows Number One resurrecting from his death in the previous episode. The bulk of the episode, however, takes place 21-22 days after "Six of One".

Cally Tyrol finds out that her husband is a Cylon and is killed by Tory Foster.
Lee Adama is making an impact in the political arena.
The Demetrius is three weeks into its scouting mission.
Natalie's faction is tricked by the Ones and lured into an ambush.

Escape Velocity

No definite markers exist, but the episode likely takes place soon after "The Ties That Bind", given that it opens with a memorial service for Cally Tyrol.

Violent clashes between Baltar's cult and other religious denominations cause a debate among the Quorum about the group's religious freedoms. They are eventually tolerated.
Galen Tyrol's grief over his wife impacts his job performance, causing a severe accident with a Raptor. After an argument with Admiral Adama, he is demoted.
Saul Tigh tries to cope with being a Cylon by talking to Caprica Six and begins to see his dead wife in her place.

The Road Less Travelled

The episode takes place 58 days into the Demetrius's mission, or 36 days after "The Ties That Bind"

When the Demetrius is scheduled to return to Galactica, it encounters a Heavy Raider with Leoben Conoy aboard, who proposes an alliance between the humans and his faction. Thrace decides to jump to his baseship, but her crew refuses and relieves her of command.
On Galactica, Tyrol despairs over the loss of his wife, confronts Baltar, but eventually makes up with him.

Faith

The episode continues directly from the previous one and the events take place over a timespan of 15 hours. In regards to the overall timeline, over three years have passed since the Cylon attack.

The standoff on the Demetrius is defused and Thrace, Anders, Athena and Barolay take Conoy to his basestar. There they meet with Natalie, who takes them to the Hybrid. They eventually repair the ship's FTL drive and return to the Demetrius.
On Galactica, Laura Roslin undergoes treatments against her cancer and socializes with Emily Kowalski‎, another cancer patient.

Guess What's Coming to Dinner?

The episode takes place shortly after the previous one.

After the Demetrius returns with the Cylon rebels and their basestar, Natalie requests the Colonials' help in unboxing the Threes and offers them the chance to destroy the Cylon Resurrection Hub in return.
Gaeta's leg has to be amputated and he deals with the loss and pain.
Both parties plan to double cross each other. The Colonials are not going to hand over the Final Five, once uncovered, and the Cylons plan to take hostages to force them to. However, Natalie has a change of heart after speaking to the Quorum and wants to call off their preparations.
Sharon Agathon, after having another vision of the Opera House fears that Natalie will take Hera from her, and shoots Natalie after she runs into the child.
Laura Roslin visits the Hybrid on the baseship, but when it is reactivated, it jumps the ship away.

Sine Qua Non

The episode continues nearly directly from the previous one, takes place concurrently with the next episode, and ends shortly before the end of the next episode.

With Roslin gone and Adama not wanting to acknowledge Tom Zarek as president, a leadership crisis erupts within the Fleet. Lee Adama and Romo Lampkin search for a suitable candidate to become interim president. The choice eventually falls on Lee Adama himself.
Admiral Adama admits that he can't live without Roslin, and decides to risk waiting alone in a Raptor at a rendezvous point, while the Fleet jumps away. He temporarily puts Saul Tigh in command of Galactica and the Fleet.

The Hub

The episode continues directly from "Guess What's Coming To Dinner?", takes place concurrently with "Sine Qua Non", spans two days, and ends shortly after the end of "Sine Qua Non".

The alliance of Cylons and humans successfully destroys the Resurrection Hub. D'Anna Biers is unboxed and demands to be returned to the Fleet before revealing anything she knows.
Roslin has visions of Elosha and hears Baltar's confession about his role in the downfalls of humanity. After the mission, the basestar returns to the rendezvous point where Admiral Adama is waiting.

Revelations

The episode continues nearly directly from the previous one

D'Anna Biers forces Saul Tigh, Galen Tyrol and Samuel Anders to reveal themselves as Cylons. The three are arrested, while Tory Foster secretly joins the Cylons.
Kara Thrace investigates her Viper and discovers a signal that gives them a bearing to Earth.
President Adama gives the Final Four a full amnesty and shares all information about Earth with the Cylons. Together they jump to the planet, but discover it be a nuclear wasteland.