at 引发的 Garbled time 的错误，请教原因。

极度善良

用kill中止了at的进程后，在打at命令，出现Garbled time的错误。请教原因


PS:这是搜出来的相关英文资料，自己看不懂
s shown, the at program accepts a fairly rich and intuitive notation. It attempts to interpret the time/date specified by parsing its command-line arguments from left to right. If its time/date specification is violated, a ``Garbled time'' error diagnostic is displayed< and the program terminates. It usually provides a terse hint as to why it became troubled.