Internet Theme Days

Internet Theme Days

Part of a series on 4chan. [View Related Entries]

Updated Mar 30, 2012 at 05:53PM EDT by amanda b..

Added Jul 26, 2010 at 01:54AM EDT by Hamilton.

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Internet Theme Days are little weekly practices within image boards and forums wherein which they have special threads created in them for the sole purpose of sharing a certain theme of images.


Caturday was the first of this string of Internet Theme Days.

Originating on 4chan’s random board, /b/, this day is dedicated to the posting of LOLCat images.

It popularized the idea of “Everyday is Caturday”, inspiring the usage of the phrase to say the same about other theme days (“Every day is X Day”), most infamously “Repost Day”. See Repost Day below for more information.

Other Popular Theme Days

A plethora of theme days have been created over the years following Caturday. Some examples of popular theme days include:


In similar vein to Caturday being a day to post images of cats, Bunday is a theme day on Monday where pictures of rabbits are often shared.

F40PH Friday

Also known as F40PHriday, F40PH Friday is a theme day when people post pictures of EMD F40PH passenger trains to counteract the posting of furry art on an overlapping theme day, Furry Friday. See Overlapping Theme Days below for more information.

Furry Friday

Furry Friday is one of the more popular theme days wherein which large amounts of furry art, usually pornographic in nature, is often posted on image boards, most infamously 4chan. This is done mostly to troll the sites.

Miku Monday

On Miku Monday, threads are created on image boards and forums for the sole purpose of sharing usually pornographic pictures of Miku Hatsune, a popular character created for a Japanese voice synthesizing program known as Vocaloid. Often times, other images of Vocaloids are posted as well.


Thorsday, or Thor’s Day as it is also called, is a theme day where people post pictures of the Norse god of thunder, Thor, on Thursdays in an attempt to post something manly.

It should be noted that the day, Thursday’s, etymology comes from the English name of this mythological god, Thunor, making it “Thunor’s Day” (the “no” dropped later on so as to sound more like the god’s Norse name).

Overlapping Theme Days

Since there are only seven days in a week, the possible choice days for an Internet Theme Day is rather limited. This causes threads dedicated to a certain theme day being spammed with images regarding other theme days. A popular example of this would be F40PH Friday and Furry Friday.

Wrong Days

Some people, on the other hand, post threads regarding a certain theme day on the “wrong” day of the week, usually proclaiming that they either missed the real date, there wasn’t enough images posted on the real date, or that they don’t care that it’s not the real date.

Repost Day

A popular derivative theme day is a phenomenon known as Repost Day, wherein which it is claimed that every single post made on the site the theme day is being celebrated on is copypasta of an older post made before it.

Forum/image board users often state that “Everyday is Repost Day” and claim that “Every Post is Repost of a Repost”.

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