TV series
The 21-Day Theory
2025, Thai, on ONE 31 & Viu.
Using the 21-Day Theory, a determined woman pursues a wealthy man to prove he's straight—but the truth defies her expectations.
- Seasons
- 1
- Episodes
- 4
- Episode length
- 45 min
- Status
- Ended in 2025
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Where to watch The 21-Day Theory
The 21-Day Theory isn’t listed on any OTT platform in India yet.
No streaming listings yet. Search JustWatch.
Latest episode
S1 E4: Episode 4
Aired 7 February 2025
Seasons 1
Cast & crew
Details
- First aired
- 17 January 2025
- Last aired
- 7 February 2025
- Network
- ONE 31, Viu
- Original title
- คลับฟรายเดย์เดอะซีรีส์ Theory of Love ไม่มีทฤษฎีไหนใช้ได้กับทุกความรัก ตอน ทฤษฎี 21 วัน
- Language
- Thai
- Country
- Thailand
- Type
- Miniseries
Check ratings elsewhere
News & fan talk
What The 21-Day Theory is based on
The 21-Day Theory is based on a true story.
Source details from Wikidata and TMDB.
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The 21-Day Theory: quick answers
Is The 21-Day Theory worth watching?
The 21-Day Theory doesn’t have enough ratings for a verdict yet.
How many seasons of The 21-Day Theory are there?
The 21-Day Theory has 1 season and 4 episodes, about 45 minutes each.
Is The 21-Day Theory finished?
Yes. The 21-Day Theory ended in 2025, so you can watch the whole story.
Which OTT platform is The 21-Day Theory on?
The 21-Day Theory isn’t listed on any OTT platform in India yet. (Checked 10 November 2026.)
The 21-Day Theory parents guide: is it suitable for kids?
No age rating is listed for The 21-Day Theory yet.
What shows are like The 21-Day Theory?
If you liked The 21-Day Theory, try Invisible Boys, You Maniac, The Newsreader.
What is The 21-Day Theory based on?
The 21-Day Theory is based on a true story.