how long; until when
Asks about the duration or endpoint of a state or action. Often used in questions or with ～か to form indirect questions.
いつまでここにいるつもりですか。
How long do you plan to stay here?
この雨はいつまで続
I wonder how long this rain will last.
いつから asks 'since when' or 'from when', focusing on the starting point, while いつまで asks about the ending point.
forever; for good; indefinitely; as long as one likes
Kanji spelling; rarely used and easily confused with なんじまで (until what time).
Kanji spelling with 迄; even rarer and may be seen as archaic or overly formal.
Compound of いつ (when) and まで (until). The kanji spellings are ateji and rarely used.