The 71-year-old has been travelling in and out of places to fulfill his promotional duties as part of the entertainer, which releases Friday.
He was in the capital Tuesday and returned to Mumbai Tuesday night to join the "rest of the family for a quiet and cozy dinner to bring in Jaya's birthday on the 9th", he posted on his blog.
"The children from Delhi are all here too and the house is filled with their laughter and play...it is the most endearing moment in the life of any parent or grandparent," Big B posted on his blog late Tuesday night.
Amitabh and Jaya got married in 1973, and together, they have two children - daughter Shweta and son Abhishek. They are grandparents to three kids - Navya Naveli, Agastya and Aaradhya.
After soaking in the joys of being with the family, Amitabh boarded a plane to Dubai for the film's premiere. He will be back in Mumbai Wednesday evening.