'admitted Until' Leave That Day Or Before?

[alphason]

Hi, Always confused by this and I should know by now...

My latest stamp for my Non-O Multiple Visa says - "ADMITTED UNTIL 18 MAY 2013" and normally I would do a border run the day before to be sure but this time I have a flight booked to KL on 13 August so will need my next admitted until stamp to cover me until this date, (there used to be a calculator for this but I can't find it).

So can I leave Thailand on 18 May? or when is the earliest I can leave so that I get a new stamp to cover me until 13 August departure?

Thanks

[Mario2008]

No problem leaving on the 18th. Normally a day before is advisable incase the car brakes down, you suddenly get sick, etc. But nothing wrong with leaving on the 18th.

[alphason]

Thanks Mario2008,

18th would be safest, but It would really suit me much better if I could go on the 16th, but not sure the new stamp would cover me until my flight on the 13 August.

[Mario2008]

May 16th would give a new 90 days, which gives a permission to stay untill 14 August.

Calculator here: http://www.timeanddate.com/date/dateadded.html?m1=05&d1=16&y1=2013&type=add&ay=&am=&ad=90&aw=

Edit:

Sorry, should be August 13th as May 16th itself would be day 1 and I should add 89 days and not 90.

[ubonjoe]

Leaving and returning on the May 18th would give you a permit to stay until Aug. 15th (May 14 days, June/Jul 61 days and Aug. the remaining 15 days) if you are getting a 90 day entry. The 16th would give you until the 13th.

Edit: Calculator posted by Mario does not appear to include the 18th in its calculation. The 90 days start on date of entry.