Place your palms together (as in praying for Christians) and bring your fingertips to the area of your eyebrows and nose. At the same time, tilt your head down and give him the traditional greeting 'Namaste' (pronounced Na-mas-tay) which means roughly 'I acknowledge that which is divine in us all'
To which the same greeting will be returned...
I don't think the time of day is so important, just follow what you would consider a normal schedule. Call the temple ahead of time and they can tell you.
Be careful, Buddhism is a beautiful religion and you may find yourself becoming more interested than you suspect. Every Buddhist monk I have ever met has been, at the same time, the most inspirational and most annoying person I have ever met.
