OTD
Of the day
Example

OTD used to mean "of the day" on Twitter
Related Slang
Usage
Last Updated: December 2, 2021
On this day
When used to mean "on this day," OTD is typically followed by a year, a referenced event, and a photo. The year is the year the referenced event took place; the photo is typically related to the event.
For example, on September 28, you might see a user post "OTD in 1998, Pokémon Blue was released in the U.S." That post would likely also contain a picture of Pokémon Blue's box art, to maximize other users' sense of nostalgia (and encourage them to interact with the post).
Example

Sports-related accounts love to use OTD to mean "on this day"
Related Slang
Usage
Last Updated: December 7, 2021
Older than dirt
OTD is a texting and chatting acronym that means older than dirt. It is commonly used by older people to describe how they feel.
"Older than dirt" is a popular saying for to exaggerate the age of something or someone. It is often utilized when talking about how one is feeling with his or her aches and pains.
Example
NM, just OTD and taking it day by day."

OTD means older than dirt
Related Slang
Usage
Last Updated: November 7, 2016
On Twitter, Instagram, TikTok, and other social media platforms, OTD often stands for "of the day." Posters use this acronym on its own and as part of other "of the day" acronyms, such as OOTD (outfit of the day), QOTD (question of the day), and WOTD (workout of the day).
For example, a user who is posting a daily series of dragon-related artwork may start a post with "Today's dragon OTD is Slifer the Sky Dragon!" Or, a user who is posting daily recipes may begin a post with "Recipe OTD: Grandma's Chocolate Chocolate Chip Cookies."