When does a TR visa start: upon application or arrival in Thailand?

The TR visa for Thailand is valid for 90 days from the date it is stamped into your passport, not from when you apply. Upon entry, you are typically stamped for an initial stay of 60 days. Although some sources mention that you need to provide a flight and hotel booking, others indicate that only intended dates are necessary. Experiences vary by nationality, and concerns about visa approval can arise, although denials seem rare if all documents are correctly submitted.