Order Cutoff Time for Premium Shipping Options - 2pm or 4pm?

I am looking at enabling one and two day premium shipping options (NOT seller fulfilled prime).

On the shipping settings page, it says ‘order by 2pm’. There is a hyperlink next to this to ‘Learn More’, and when clicked, opens a page which says ‘The order cut-off times for your Premium Delivery options orders must be set to at or after 4:00 p.m. local time’

Can anyone using premium shipping advise which time it actually is? 2pm is fine, but if it’s 4pm, it becomes an issue as our post pickup is usually prior to that!