Do I have a maximum of 90 days to enter?

[notasmartassknowitallfarag]

Thailand with a non B visa before it expires? Trying to not go to the embassy too soon. 

[elviajero]

If it’s a single entry visa it will be valid for 3 months from the date it’s issued. The ‘enter before’ (use by) date will be printed in the visa. So you’ve got 3 months to enter.

[Tanoshi]

Many confuse the validity of the Visa with the validity of permission to stay.

 

As eljiavero stated a single entry Non B Visa will be valid 3 months from the date of issue.

You can enter on the last day of the Visas validity and you will still be given 90days permission to stay.