If I get a Single Thai Tourist Visa on August 1, what is the latest possible date on which I'm allowed to enter Thailand?

And starting from that latest possible entry date, can I stay for 2 more months in Thailand?

Whatever is indicated on the visa itself but validity is 3 months from date of issue to use Yes you will receive the full 60 day entry up until that date and can extend the normal 30 days later.

you can actually stay upto 3 months in thailand because after the 60 days runs out you have an option to extend an extra 30 days for 1900 baht.

tourist visas are valid for 3 months from issue or sometimes 6 months depending on where you get it from,

i would imagine all single entries are valid for 3 months from issue, i don't know if they count whole months or wheather it's 90 days,

best option is to extend or it's 500 baht a day overstay fine, i think a 1 day overstay they don't charge.

Look at your visa it will say enter before__________ a particular date.

He does not have a visa - he is asking for a future visa - the validity will be 3 months from date of issue.