The AMCAS open-for-submission date is this Thursday, May 27. While submitting on Thursday is to your advantage because of rolling admissions, getting that application in at 9:30am EST on May 27 is not worth losing your mind over, so if you simply can't, please don't kick yourself.
If you're wrapping up your work and have your written materials in a superior state, just keep moving and get your application submitted promptly. If you're behind the eight ball and don't feel that you can craft outstanding written materials speedily, consider waiting a year to apply. Every season I encounter re-applicants who, during the previous cycle, submitted their AMCASes in August or September...thus making them re-applicants :(.
