month of Sundays

1. 很长的时间
   It will take us a month of Sundays to finish this work.

   完成这项工作我们要花很多的时间。

for months

1. 好几个月
   I've stayed there for months.

   我在那儿已住了好几个月。

month after month

1. 一月一月地，月复一月
   If you do the same things month after month, you may get bored.

   如果你每月都做同样的事情，你可能会感到厌烦。

month in, month out

1. 每月
   I do the same things month in, month out.

   我每月都做同样的事情。

• a month of Sundays
  informal a very long time.