The day is returned as an integer in the range 1 (Sunday) to 7 (Saturday) if Type is omitted or Type = 1 is specified. If Type = 2, numbering begins at Monday = 1; and if Type = 3 numbering begins at Monday = 0.
如果没有指定类型或 type=1，则返回的日期为在 1 （星期日）到 7 （星期六）之间的整数。如果 type=2，则编号起始为星期一=1；如果 type=3，则编号起始为星期一=0。