如果您有gnu日期，这应该可以工作：

this should work if you have gnu date:

1 day ago <month> 1

< month> 例如，

kent$  date -d'1 day ago may 1' 
Tue Apr 30 00:00:00 CEST 2013

另一个示例，查找7月之前的月份的最后一天：

another example, find the last day of the month before July:

kent$  date -d'1 day ago july 1'
Sun Jun 30 00:00:00 CEST 2013

请注意，时间戳记设置为 00:00:00 。

note that, the timestamp was set to 00:00:00.