求用英语表示时间所要加的介词和询问星期几 几月几号等句型

1,what's the date today?今天是几号?
2,what day is it?今天是哪一天?/今天是几号?
3,what's the time?几点了?
4,what time is it?几点了?
1和2同义,3和4同义.