All forms filed via TEAS are time/date stamped when received on the USPTO server, according to Eastern Standard Time (EST). The time/date stamp is applied at the moment the payment process is completed and the success screen is displayed. The time/date stamp applied by the TEAS server is the official time the USPTO received the application or form; the time the transmission began is not a factor considered when assigning the filing date. The official filing date and time can be found at the bottom of your e-mail confirmation. Any submission that arrives as of 11:59 p.m. EST will be given that day’s filing date (i.e., regardless of USPTO’s “normal” business hours).