那是壹個周日的下午的英文是It was a Sunday afternoon。
Sunday是星期天的意思。afternoon是下午的意思。星期壹的英文是Monday，星期二的英文是Tuesday，星期三的英文是Wednesday，星期四的英文是Thursday，星期五的英文是Friday，星期六的英文是Saturday，星期日的英文是Sunday。類似句子如下：
1、周二晚間和周三早晨也是最佳觀賞時間。
Tuesday night and early Wednesday morning are also good observation times.
2、周三早晨他將接受手術。
He will now have an operation on Wednesday morning.
3、壹次7.1級地震在本周三早晨襲擊了這個縣城。
A 7.1-magnitude quake struck the county on Wednesday morning.