A weekday; an ordinary (non-holiday) day. Also used adverbially (e.g. "on weekdays").
平日は仕事で忙しく、週末しか買い物に行けない。
I'm busy with work on weekdays, so I can only go shopping on weekends.
この店は平日は九時まで営業しています。
This shop is open until 9 o'clock on weekdays.
子供は平日学校に行き、休日は家で過ごすことが多い。
Children go to school on weekdays and often spend holidays at home.
平日は通勤ラッシュで電車が混む。
Trains are crowded during the commuting rush on weekdays.
The kanji radical number 73 (the '平' radical) — used in kanji classification.
『平』は部首73番に分類される（平日・平成の『平』など）。
The character '平' is classified as radical number 73 (as in 平日, 平成).