day of the month
Attaches to numerals to express a specific day of the month, e.g. 一日 (ついたち), 二日 (ふつか), 三日 (みっか). Note the irregular readings for some days.
What day of the month is it today?
Used after a number to count days, e.g. 一日 (いちにち), 二日 (ふつか), 三日 (みっか). Note the irregular readings for small numbers.
The trip was for three days.
The meeting was postponed to the 3rd.
Summer vacation ends in two more days.
Also means 'day' but is used in different contexts, such as days of the week (e.g. 日曜日) or as a counter for days in formal/legal contexts (e.g. 第１日).
Means 'day' as a standalone noun, often referring to a day in general or a specific date, e.g. その日 (that day).
hangover
New Year's Eve
crescent moon; new moon
quitter; someone who can't stick to anything
last day of the month; month-end day
Standard kanji spelling for the suffix and counter meaning 'day'.
The reading か is the native Japanese (kun'yomi) for the kanji 日, used specifically in counting days and dates. The irregular readings for the first ten days (ついたち, ふつか, etc.) are remnants of Old Japanese.
5th day of the month · five days
6th day of the month · six days
7th day of the month · seven days
8th day of the month · eight days
9th day of the month · nine days
10th day of the month · ten days
20th day of the month · 20 days