Date Reverting Back One Day

When we enter in a date for a class – say July 25 – and then post the class the date will revert a day backward – to July 24. If we go back into the class details and update it will stick.

I’m not sure if this is a plugin issue or a general WordPress issue.

Any help on where I can look for a resolution would be helpful.

http://wordpress.org/extend/plugins/simpul-events-by-esotech/