What is the entry timeframe for an ED visa issued outside of Thailand?

Hi there,

Have a query about the ED visa and was not able to find the specific answer in the search function.

Once you are issued the ED visa while outside of Thailand, within which timeframe do you need to enter Thailand.

Let’s say the ED visa starts July 1, are you to enter the country on that date and start at the same time at the school. Not sure that is even possible.

Or is the ED visa just the start of when you enter Thailand and you setup the time with the school thereafter to join their program.

How has your experience been on this topic?

Many thanks,

Jan