間日
also: あいび
Meanings
1
day off between working days
A day off sandwiched between working days, often used in scheduling contexts.
Next Wednesday is a day off between working days, so I can rest well.
2
50th, 53rd, 55th or 59th day of the sexagenary cycle
Technical term in the traditional Chinese sexagenary cycle (干支). Rare outside historical or calendrical contexts.
See also: 干支
The 間日 in the sexagenary cycle can have special significance in the calendar.
3
non-fever day (intermittent fever)
Medical term for a day without fever in intermittent fevers like malaria. Rare in modern usage.
A malaria patient's fever subsides on non-fever days.