noun
time to give one's all; time to do one's best; time to shine
Used when a crucial moment demands maximum effort, such as an exam, competition, or career-defining task.
ここが頑張り時だ。
This is the time to give it your all.
受験生にとって、夏休みは頑張り時です。
For exam candidates, summer vacation is the time to do their best.
正念場 is a decisive moment or critical juncture, often with a more serious or dramatic nuance than 頑張り時.
Compound of 頑張り (continuative form of 頑張る, 'to do one's best') and 時 (とき, 'time'), with rendaku voicing of とき to どき.