Passport is a must if you have to apply for GMAT. So if you don't have it then apply asap coz you will get it within a month . See for yourself which time of the day you are comfortable giving the test . Take practice test and you will come to know about your preference. My suggestion take it either in the morning slot i.e 0900 hrs-1030 hrs or the evening slot i.e 1600-1700 hrs . Best of luck
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