getdate函数
描述：可以获取日期/时间信息
语法：array getdate( [ int timestamp ] )
返回一个数组 例：
Array
(
[seconds] => 30
[minutes] => 59
[hours] => 10
[mday] => 31
[wday] => 2
[mon] => 3
[year] =>2020
[yday] =>90
[weekday] => Tuesday
[month] => March
[0] => 1585623570
)
