子供はもう寝る時間ですよ。
tbd
It's high time the children went to bed.
It's time for children to go to bed.
It's high time you children went to bed.
は
1. indicates sentence topic
2. indicates contrast with another option (stated or unstated)
3. adds emphasis
指示句子的主题;表示与另一选项(无论是否明确提及)形成对比;表示强调