erc-timestamp-use-align-to

erc-timestamp-use-align-to is a variable defined in `erc-stamp.el'.
Its value is

nil

Documentation:
If non-nil, use the :align-to display property to align the stamp.
This gives better results when variable-width characters (like
Asian language characters and math symbols) precede a timestamp.
Unfortunately, it only works in Emacs 22 and when using the X
Window System.

A side effect of enabling this is that there will only be one
space before a right timestamp in any saved logs.

You can customize this variable.