Nowadays, it is quite common in many parts of the world to celebrate particular days for special people in our lives. So we have the Mother's Day, Father's day and suchlike. However, In India, Bengali mothers-in-law have traditionally celebrated, with great fanfare, an occasion/social custom called jamai shashthi  – a special day for their jamai [son(s)-in-law].
On this auspicious day, the married daughter and the the son-in-law are invited by the girl's parents and the son-in-law is honored, treated to a scrumptious meal and pampered with gifts by his mother-in-law. Sons-in-law look forward to this day and if you happened to visit Kolkata on 17th June this year (which is when jamai shashthi was celebrated this year), chances are you would have seen a significant number of married men rushing off early from office so as not to miss the occasion when he would be treated like a king by his mother-in-law.
Blogger Poo recalls jamai shashthi as being a ‘day of fun’. She writes :
Moms-in-law fast and pray for their son-in-laws. This day earlier meant a lavish lunch at Dida's (maternal grandmother) place where not only dad but all of us got gifts by the truckload… We'd wear new clothes and eat yummy food. It was a day of fun
In a light-hearted post, Kamalika points out  the ‘real reason’ why this day was traditionally celebrated by the in-laws. She says:
It used to be a kind of bribe given to Jamais by their in-laws for keeping their daughters happy.
Aritra offers  a humorous take on the day's proceedings and notes how it is sometimes easy to guess whether the son-in-law is ‘brand new’ or has been around for sometime. According to him:
its this very interesting custom followed amongst bengali mother in laws where they pamper, feed, gift their son in laws – all in a day! … jamais do fare well in this custom but all depends which model are they – as in a brand new one or the one people often mistakes as the son. brand new ones are less on talking and show some restriction in movements except a constant bowing down to elders to touch their feet and being introduced to whole new faces. they get the same reaction from the people they meet – biyete dekhechilam ..tarpor ei kotah holo (i last saw you in the marriage ceremony…and now we get to talk) . with a sheepish smile he escapes all these and makes his way to the plate and the platter. advice for new ones, do avoid second helpings as the options are too many ! advice for old ones, you know what to avoid already!
then there are gifts! from both the sides. often getting restricted to clothes! but innovations are always welcome! for this one day, your mother in law , if she is the kind, restricts her daughter from interfering and its like the husband (WOW) becomes really important !the rest of the 364 days its always the other way round (ya ya we know)!
Nowadays, life is getting busy and children often live far away from their parents. That notwithstanding, the celebration of jamai shoshthi continues to survive, having undergone some mutation  [bn] in these cases. Long distance calls are made to wish the son-in-law living in distant lands, restaurants in the city lay out lavish jamai shashthi spreads for the busy Bengalis who no longer have the time or patience to whip up traditional delicacies, and parents use the webcam to consult with their children regarding gift purchases.
Nowadays, married men should also work towards deserving a jamai shashthi, quips Kamalika and offers some advice  to men who hope to be feted by their shashuri (mother-in-law):
so to all my guy friends who are married… learn to earn the treat and gifts for Jamai Shoshti, otherwise…. your day might not turn out the way you imagined it in your head! You could say good bye to second helpings, sumptuous food and any respect given to you for that matter! Coz in this world nothing comes for free… So to earn the platter learn to flatter your shashuri and your wife all year long…!
It is interesting to note that Jamai Shashthi was also the name of the first Bengali talkie  released in 1931. Aritra jokes,
so the son in law added the dimension of sound to an otherwise silent era!