今いままで

い

ま

で

Meanings

Describes a state or action continuing from the past up to the present moment. Often used with past-tense verbs or present-perfect-like expressions.

今いままで〈動どう詞し〉たことがないhave never done ~ until now
今いままで海かい外がいに行いったことがない。
I have never been abroad until now.
今いままで〈動どう詞し〉てきたhave been doing ~ up until now
今いままで一人ひとりで頑がん張ばってきた。
I've been working hard on my own until now.
今いままでに〈数かず〉by now, ~ times/amount so far
今いままでに三さん回かい失しっ敗ぱいした。
I've failed three times so far.

これまでN1
今まで is strictly temporal (until now), while これまで can also mean 'up to this point' in a spatial or figurative sense.
かつてN2
今まで means 'up until now' and centers on the span leading to the present, while かつて with a negative verb stresses that something has never occurred at any point in the past.
従じゅう来らいN2
今まで is neutral and common in both speech and writing, whereas 従来 additionally carries the nuance of something 'conventional' or 'existing' when used before の.

今いまから
今まで points backward from the present (until now), while 今から points forward from the present (from now on).
これからN5
今まで looks back at the time before now, whereas これから looks ahead to the time after now.
今こん後ごN3
今まで means 'up until now,' looking back at the past, while 今後 means 'from now on,' looking forward to the future.

今いままで
Standard kanji spelling; high-frequency in news and everyday writing.
今いま迄まで
rarely-used kanji form
Rarely used kanji form; 迄 is a non-jōyō kanji and is usually written in kana.

Compound of 今 (ima, 'now') + まで (made, 'until'). The kanji 迄 is an older form for まで, now rarely used.