The end date on the admission record governs, not a count of trips or an assumption that a new entry resets everything. Note that date after each entry and plan any extension or new admission well before it arrives, with the employer's confirmation in hand.
Work backwards from the recorded end date
Set a reminder tied to the actual date on the record rather than an approximate period. If the engagement is expected to continue past it, start gathering the employer's updated letter and any refreshed evidence weeks ahead, since collecting documents from a different country on short notice is what most often causes a gap. Do not assume a filed request permits continued work.
If the start date shifts or the employer changes the role, some preparation may need redoing, and agreeing in advance what a change costs is easier than negotiating mid-file. Build backwards from the proposed first workday and allow time to correct a letter, obtain an original credential, or resolve a name difference. Keep a saved copy of the actual admission record somewhere accessible while traveling, rather than relying on memory or an old calendar note, since the recorded date is what controls. Where a family member's authorized period is tied to the same file, check that date separately rather than assuming it matches automatically. A petition's own validity window is a distinct date from the admission record and both should be tracked on their own line, not merged into a single reminder.