- A leading charactor for day is space.
- Time zone does not included.

Before this patch:

  Time.gm(1982,3,4,5,6,7).asctime  #=> "Thu Mar 04 05:06:07 UTC 1982"

After this patch:

  Time.gm(1982,3,4,5,6,7).asctime  #=> "Thu Mar  4 05:06:07 1982"