How I met your mother
A full list of special holiday episodes

Follow the hilarious and heartfelt antics of five friends in New York City as one of them navigates his way through the ups and downs of finding love.
The show aired 7 Christmas episodes, 5 Thanksgiving episodes, 2 Halloween episodes, and 1 Valentine's Day episode.
Christmas episodes:

Season 1, Episode 11
The Limo
Ted rents a limo for New Year's Eve 2005 and plans a night of celebration with the gang, but things don't go as expected.

Season 2, Episode 11
How Lily Stole Christmas
Lily takes down her Christmas display after Ted insults her during her breakup with Marshall, and Barney falls ill.

Season 4, Episode 11
Little Minnesota
Ted tries to keep his sister from hooking up with Barney while she's visiting New York, and Robin hides her Canadian identity from Marshall and his Minnesota friends.

Season 6, Episode 12
False Positive
Barney and Robin consider making significant life changes after learning that Lily is pregnant. However, they change their minds when Marshall and Lily reveal that it was a false alarm.

Season 7, Episode 12
Symphony of Illumination
Barney and Robin receive unexpected news after Robin tells Barney she's pregnant. Meanwhile, Marshall is pranked by a teenager while decorating for Christmas.

Season 8, Episode 11
The Final Page: Part One
Ted wants to show off his new building to an old professor, Barney is stuck in a jinx, and Marshall and Lily bump into an irritating old friend. Robin is offered a chance to fire Patrice.

Season 8, Episode 12
The Final Page: Part Two
Ted is torn between keeping a promise to Barney and telling Robin about his proposal plans, and taking her as his date to the opening of his new building. Meanwhile, Marshall and Lily look forward to a rare night out.
Thanksgiving episodes:

Season 1, Episode 9
Belly Full of Turkey
Marshall's Thanksgiving with his family becomes tense when Lily suspects she might be pregnant. Meanwhile, Robin, Barney, and Ted spend the holiday volunteering.

Season 3, Episode 9
Slapsgiving
Marshall prepares to deliver the third slap to Barney on Thanksgiving while Ted and Robin hook up the night before the holiday.

Season 5, Episode 9
Slapsgiving 2: Revenge of the Slap
Barney becomes anxious when Marshall gives Ted and Robin the power to slap him as part of a bet. Lily's father unexpectedly arrives for Thanksgiving dinner and Robin starts frequenting a Minnesota-themed bar.

Season 6, Episode 10
Blitzgiving
Ted plans a Thanksgiving dinner for his friends, but leaves early and misses out on all the fun with an old college friend nicknamed The Blitz. The rest of the gang has a wild night, leaving Ted to spend Thanksgiving with Zoey instead.

Season 7, Episode 11
The Rebound Girl
Robin opposes Marshall and Lily's plan to move to Long Island, while Ted and Barney decide to become "bro-parents."
Halloween episodes:

Season 1, Episode 6
The Slutty Pumpkin
Marshall and Lily attend a Halloween costume party, while Robin introduces her new boyfriend. Meanwhile, Ted and Barney go to their annual Halloween party, where Ted searches for his lost love, the Slutty Pumpkin.

Season 7, Episode 8
The Slutty Pumpkin Returns
Ted reconnects with his long-lost crush from a Halloween party, while Lily's "pregnancy brain" convinces her to move to the suburbs. Barney discovers he's one-quarter Canadian.
St. Valentine's Day episodes:

Season 6, Episode 16
Desperation Day
Lily heads to Minnesota to convince Marshall to come back, but he's not ready to leave. Meanwhile, Ted and Zoey's relationship faces challenges, and Barney tries to find a date for Valentine's Day.