It's celebrated on the 6th of December as per a popular Indian sitcom named "Lucen". On this day, the 5 lead characters (Ashish, Kena, Manas, Prateek, and Sunil) happen to celebrate a friend's reunion after separating. The friends parted ways in the last episode of season 4 aired in June 2022.
prateek: we shall celebrate Lucen day in Hyderabad this year.
sunil: cool, but why?
prateek: because you and me are already in south, and manas is always in the bus from south to north. duh!
It's celebrated on 17th of August as per the popular Indian sitcom named "Philophers". The character Sid, who goes by the name "beerbottle", makes it rain beer for his friends. His friends start calling it the Sid-day.
yasho: bruh, why is it raining beer today?
sunil: brah! it's sid-day gif!
kena: here, fill my cup too. i can't come.
rajjo: wait. i am coming too.
It's short for "Aaj Maine Jana". This is a Hindi version of "Today I learned". It is popularized by the subreddit r/AajMaineJana
raj: amj, how railway tunnels are cleaned.
me: so, where you gonna use this knowledge then?
It's celebrated on 4th of May as per a popular Indian sitcom named "Philophers". On this day, you can only use GIFs and not words to reply in chats. This is majorly popular in Bihar, Uttar Pradesh, Gujarat, and Rajasthan states of India.
yasho: bruh, it's indian gif day, finally!
sunil: yes i know murga gif!
yasho: "agreeing gif"