邮件截止日
邮船开航日

packet \pack"et\ (p[a^]k"[e^]t), n. [F. paquet, dim. fr. LL.
paccus, from the same source as E. pack. See {Pack}.]
1. A small pack or package; a little bundle or parcel; as, a
packet of letters. --Shak.

2. Originally, a vessel employed by government to convey
dispatches or mails; hence, a vessel employed in conveying
dispatches, mails, passengers, and goods, and having fixed
days of sailing; a mail boat.

{Packet boat}, {Packet ship}, or {Packet vessel}. See
{Packet}, n., 2.

{Packet day}, the day for mailing letters to go by packet; or
the sailing day.

{Packet note} or {Packet post}. See under {Paper}.