Short answer
HubSpot's KB: timing uses your account's time zone; with none set, it defaults to EST. Timing settings affect actions after enrollment, not enrollment itself. Pause dates combine with day and time limits when rescheduling.
1. In HubSpot
The relevant screen in my demo portal.

2. Worth knowing
Check the account time zone before blaming the workflow.
3. Related
Workflow settings and account time zone.