Japanese DictionaryDefinition of 思い立ったが吉日
- (exp) no time like the present; make hay while the sun shines; it's the auspicious day when you've just thought of it
思い立ったが吉日、さっそくプロジェクトの企画案を書き始めよう。
Quick let's get started on the project proposal while the idea is still fresh in our minds. There's no time like the present.