SpongeBob SquarePants/Timeline

An as-of-yet incomplete timeline of the show SpongeBob SquarePants. This will only count the show's episodes and tie-in movies if it fits.

Year ?
Hall Monitor (S1E7a)
 * At the end of the episode, SpongeBob is learning about what traffic lights are, meaning it takes place pretty early during this year at boating school.
 * Mrs. Puff is in prison for 6 months.

I Was a Teenage Gary (S1E13b)
 * This is Squidward's first time meeting Gary.
 * Spongebob only has Squidward to take care of Gary, making it take place before episodes where Spongebob has other friends to take care of Gary.
 * SpongeBob has an entire weekend free, despite Sunday being a work day as seen in Squid's Day Off, making it take place before Help Wanted.

Something Smells (S2E2a)
 * It's Sunday the 20th, despite Sunday being a work day at the Krusty Krab as seen in Squid’s Day Off, making this take place before Help Wanted.
 * Spongebob gets bad breath.

Squidville (S2E6b)
 * SpongeBob gets his reef blower for the first time.

Reef Blower (S1E1b)
 * Only Spongebob and Squidward are here.
 * Spongebob has a reef blower, making it take place after Squidville where he purchased one.

Bubblestand (S1E2a)
 * Spongebob is earning quarters via a bubblestand and bubble-blowing lessons, meaning it takes place before Spongebob gets a paid job.
 * Patrick and Squidward learn how to blow bubbles, making it take place before they actually blow proper bubbles.

Opposite Day (S1E9b)
 * Squidward can only blow simple bubbles, meaning it takes place after Bubblestand.
 * This is likely very early in the timeline and provides an explanation as to why Squidward can't simply move away.

Naughty Nautical Neighbors (S1E4a)
 * Patrick and Squidward know how to blow bubbles, making this take place after Bubblestand. They can also make bubbles with messages hidden inside, making it take place after Opposite Day due to Squidward only blowing simple bubbles.
 * Spongebob only has Patrick and Squidward as his friends, making it take place before episodes such as Tea at the Treedome where Spongebob befriends Sandy.

Help Wanted (S1E1a)
 * SpongeBob gets hired at the Krusty Krab, making it take place before episodes where he's working.

Hooky (S1E20a)
 * Squidward can't cook krabby patties, making this take place before Employee of the Month.
 * Mr. Krabs has said that nobody has taken a break at the Krusty Krab for a long time, making this take place before any other break.
 * Spongebob seems unacquainted with Pearl.

A Life in a Day (S6E5b)
 * Incidental 14 doesn't know who Larry is, making it take place before Ripped Pants, where she saw Larry.
 * Larry doesn’t know Spongebob and Patrick nor respects them, making it take place before Ripped Pants where Larry asked for SpongeBob's autograph.
 * Patrick doesn’t want to waste his life blowing bubbles, making it possibly take place after Bubblestand where they were interested in blowing bubbles.
 * Spongebob works at the Krusty Krab, meaning it takes place after Help Wanted.
 * Larry becomes the Goo Lagoon lifeguard.

Tea at the Treedome (S1E1c)
 * Spongebob and Patrick are introduced to Sandy.
 * Spongebob says he also loves karate, possibly trying to have an exciting life after A Life in a Day.

Fools in April (S1E19a)
 * It's April Fools, making this episode take place April 1st.
 * Squidward mentions Sandy, making this take place after Tea at the Treedome.

Squid's Day Off (S2E1b)
 * It's Sunday.
 * Spongebob doesn't know how the cash register works, making this pretty early in Spongebob’s time at the Krusty Krab.
 * Squidward has absolutely no trust in Spongebob being alone at the Krusty Krab, making this pretty early in Spongebob’s time at the Krusty Krab.

Bubble Troubles (S8E15a)
 * Sandy gets air from SpongeBob and Patrick.
 * Squidward has been working on a Squidward-shaped bonzai tree for 20 years.
 * Patrick doesn't call himself a doctor, making it take place before Suds where he impersonated a doctor.

The Good Krabby Name (S8E25a)
 * Squidward's duty is cleaning the Krusty Krab, continuing his duty from Help Wanted.
 * Incidental 11 hasn't been at the Krusty Krab, making this take place before Texas, where she's at the Krusty Krab.
 * Incidental 15 hasn't been at the Krusty Krab, making this take place before Squirrel Jokes, where he's at the Krusty Krab.
 * Incidental 17 hasn't been at the Krusty Krab, making this take place before Cuddle E. Hugs, where he's at the Krusty Krab.
 * Incidental 18 hasn't been at the Krusty Krab, making this take place before Pickles, where he's at the Krusty Krab.
 * Incidental 28 hasn't been at the Krusty Krab, making this take place before Mermaid Man and Barnacle Boy IV, where he's at the Krusty Krab.
 * Incidental 64 hasn't been at the Krusty Krab, making this take place before Pickles, where he's at the Krusty Krab.
 * Incidental 87 hasn't been at the Krusty Krab, making this take place before Spy Buddies, where she's at the Krusty Krab.
 * Incidental 91 hasn't been at the Krusty Krab, making this take place before My Pretty Seahorse, where he's at the Krusty Krab.
 * Incidental 92 hasn't been at the Krusty Krab, making this take place before Squirrel Jokes, where he's at the Krusty Krab.
 * Incidental 158 hasn't been at the Krusty Krab, making this take place before Skill Crane, where he's at the Krusty Krab.

Texas (S1E18a)
 * Spongebob first learns about Texas traditions.
 * Spongebob and Sandy play karate together, but they don't use foam hands yet.
 * Incidental 11 and 18 are at the Krusty Krab, making this take place after The Good Krabby Name, where they're part of the incidentals that haven't eaten at the Krusty Krab
 * Pearl is Sandy's friend, making this take place after Bubble Troubles, where their friendship is purely based on both being mammals.
 * Mrs. Puff and Karen aren't there to cheer Sandy up, which means this takes place before Girls' Night Out, where the three form the Gal Pals

'''Christmas Who? (S2E8)'''
 * Sandy teaches Spongebob, and in turn the rest of Bikini Bottom, about Christmas traditions.
 * Spongebob uses foam hands for karate.
 * Spongebob knows about Sandy’s Texas heritage, making it take place after Texas.
 * Plankton is only receiving a gift from Mr. Krabs, suggesting Plankton is only acquainted with Mr. Krabs at that time.

Year 2
Jellyfishing (S1E3a)
 * Patrick knows about Christmas, making this take place after Christmas Who?.

Year ?
Nautical Novice (S6E2b)
 * This implies Mrs. Puff's first time honestly giving SpongeBob his driver's license.
 * SpongeBob's driver's license expires in 2003, making it take place before any episode after 2003.
 * This episode takes place close to or in December, judging by the driver's license expiration date.

No Free Rides (S2E10a)
 * Mrs. Puff gives SpongeBob his driver's license, which will expire in 2003.
 * SpongeBob's driver's license expires in 2003, making it take place before any episode after 2003.
 * This episode takes place close to or in December, judging by the driver's license expiration date.

Girls' Night Out (S11E48)
 * The Gal Pals exist at this time.
 * Sandy was out being an ameba for a week.
 * Mrs. Puff has been teaching Spongebob for years.
 * Karen says she has lived with Plankton for 27 years.
 * Plankton is on probation.
 * Spongebob's virtual reality driving license expires in 2003, making it take place before any episode after 2003.
 * This episode takes place close to or in December, judging by the driver's license expiration date.

Sleepy Time (S1E30)
 * The appearance of Spongebob’s driving license might’ve been influenced by his license in Nautical Novice, No Free Rides, and Girls' Night Out.
 * Pearl greets Spongebob pretty happily, making this take place after The Chaperone, where Pearl grows comfortable around him.

Year ? (2)
SB-129 (S1E14a)
 * Spongebob works at the Krusty Krab at that time.
 * This episode apparently takes place in 2017, as it's 4017 2,000 years later.
 * It's also March 8th.
 * Squidward is frozen in the Krusty Krab freezer, making this take place after any episode exploring the Krusty Krab's freezer.

Year 31
The Spongebob Squarepants Movie
 * Spongebob becomes the manager of the Krusty Krab 2.
 * SpongeBob has been working at the Krusty Krab for 31 consecutive years.
 * This is Plankton's last thought-out plan to steal the Krabby Patty secret formula.

Spongebob’s Big Birthday Blowout (S13E13-14)
 * It’s Spongebob’s birthday.
 * Spongebob knows Frenchy to be Sandy’s friend, making it take place after Feral Friends.
 * Mindy appears at Spongebob’s birthday, meaning it takes place after The Spongebob Squarepants Movie where Mindy introduces herself to Spongebob.
 * David Hasselhoff promises to move to a volcano, meaning it takes place after The Spongebob Squarepants Movie where Hasselhoff worked as lifeguard.