Hello Niyamkathuria!
Traveling Merchant has different items and prices everyday, It is not always the same stuff everyday! The daily refresh for Travel Merchant towards the Indian Times is 23:30 Everyday!
Zookeeper normally comes around in Indian Timezones between 22:30 - 00:00 every Friday! Just keep an lookout on the Restock or the easier method, if people are surrounding the Zookeeper.
Best Regards,
pmjk