Thailand Sim Card Exp Date

[THAIBUS]

I am going to Thailand on 28/05/2013 and brought two 12CALL Thai local sim cards on the internet to use while out there.
I was going to activate them as soon as I arrive in the country.
On the back of the SIM cards it says EXP. DATE 05/2013 and I just wonder if any one knows if they will expire on the first of may or the last day in May. Many thanks to anyone who may help.

[SlackAlice]

Most of the tourist sim cards only have a validity of 30 days whether the credit has been used or not. I suspect your expiry date will be end of May 2013.

Whenever I go to Thailand now, I buy my Thai sim at the airport. There are always several kiosks selling them in hot competition. Be aware most of them are the micro sim cards so make sure they give you the adaptor as well.