I am on a tourist visa but would like to convert to an ed visa. The ed visa gives you 90 days at a time. If I convert, will the first 90 days of the ed visa run from the date of entry into Thailand or the date when the visa was converted?

The date when the visa was converted. 

It starts on the day you apply. You will only be able to apply one time for a non-ed visa unless you leave and re-enter the country with a new tourist visa or a visa exempt entry.

After getting the non-ed visa entry you would apply for a extension of stay based upon attending school.

7 minutes ago, ubonjoe said:

It starts on the day you apply. You will only be able to apply one time for a non-ed visa unless you leave and re-enter the country with a new tourist visa or a visa exempt entry.

After getting the non-ed visa entry you would apply for a extension of stay based upon attending school.

 

The last time I applied for a conversion to a Non O, the visa date and the associated initial 90-day stamp had the date the visa was issued, which was about 10 days after I submitted my application. Has this now changed?

3 minutes ago, BritTim said:

The last time I applied for a conversion to a Non O, the visa date and the associated initial 90-day stamp had the date the visa was issued, which was about 10 days after I submitted my application. Has this now changed?

There have been several reports and the stamps posted that showed the visa issued on the day a person applied and a entry stamp as well. Some offices might do it differently.

At Chiang Mai immigration a non-immigrant visa starts at the day you apply.

I entered on a VE - then converted to a ED visa from within Thailand - the date of the ED Visa started from the day I entered Thailand so I got around 11 months stay on it

24 minutes ago, darrendsd said:

I entered on a VE - then converted to a ED visa from within Thailand - the date of the ED Visa started from the day I entered Thailand so I got around 11 months stay on it

An ED visa only gives permission to stay for 90 days, so how could you get 11 months out of it?

30 minutes ago, jackdd said:

An ED visa only gives permission to stay for 90 days, so how could you get 11 months out of it?

90 + 90 etc - extended at Immigration