PREPOSITIONS 2

Due by 2 p.m.: 2 p.m. is the deadline; earlier is allowed. Due at 2 p.m.: the deadline is 2 p.m. Due on Monday: Monday is the deadline day.

Have until 6 p.m. to send it: your available time ends at 6. Work until 6: continue working to 6. Do not send it until 6: wait; do not send it before 6.

A payment is due to Mark: Mark is owed the payment. The delay is due to traffic: traffic caused the delay. Mark is due to arrive: Mark is expected to arrive. For a delivery instruction, use Get it to Mark by 2 p.m.

Since 2: from 2 until now, in an appropriate present-perfect sentence. For two hours: a duration. Within an hour: no more than one hour from the stated starting point. In an hour: usually about one hour from now in a future statement; with “completed,” it can measure the time needed.

On time: at the scheduled time. In time: soon enough for a purpose. Early / late: before / after the expected time. Say after the deadline or after the scheduled time, rather than “after time” for a missed deadline.

At 2: a clock time. On the hour: exactly 2:00, 3:00, etc. At the hour stated in the notice: at that specified time. In the hour before lunch: during that particular period. The published time: the time listed in a schedule; this is usually more natural than “the published hour.”

These questions use ordinary deadline language. A real service may specify an exact cutoff or require receipt rather than sending; follow its stated instructions.