In medicine, morning and afternoon are represented by letters, such as am in the morning and pm in the afternoon.

In medicine, the letters are am, pm, h, m in and min.

Qd once a day, bid twice a day, tid three times a day and qid four times a day.

Qh every hour, q2h every 2 hours, q6h every 6 hours.

Qm is once every morning (note the difference between qn and afternoon, once every night, qod once every other day.