日時|にちじnichiji[1]atamadaka (head-high)

1. noundate and time (of a meeting, departure, etc.)
   あなたの都合つごうのいい日時にちじにミーティングを組み直くみなおしてくださいませんか。↗

   Could you please re-schedule the meeting at your convenience?
2. noundays and hours

• Related日付ひづけNeutralNeutral: the date itself, as in 「日付を書く」; it carries no time of day, while 「日時」 is date plus time.
• Related日にちひにちCasualColloquial: a day, a date, or a number of days, as in 「日にちを決める」; no time of day included.
• Related期日きじつWrittenWritten/formal prose: a fixed date or deadline, as in 「支払期日」; leans toward due or appointed dates.
• Related日取りひどりNeutralNeutral: the day picked and fixed for an event, as in 「結婚式の日取り」; stresses settling on a date.
• Related年月日ねんがっぴWrittenWritten/formal prose: year, month and day together, often on forms, as in 「生年月日」; no time of day.
• Related時日じじつWrittenWritten/formal prose: date and time, but also a span of days, as in 「時日を要する」.
• Related開催日かいさいびNeutralNeutral: the day an event is held; date only, so its range is narrower than 「日時」.

Use 「日時」 when you need both date and time, as in 「集合日時」. For the date alone use 「日付」 or 「日にち」; for deadlines 「期日」; for a settled day 「日取り」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 日付ひづけと時刻じこく。
2. 日数にっすうと時間じかん。