Download Resyncsub, a simple Ansi-C command line utility for editing subtitle files (delay, scale time, split and translate between .ssa, .srt and .sub files)
This software is intented for manipulation of Subrip (.srt), Subviewer (.sub)
and SubStation Alpha (.ssa) subtitle files. It is possible to delay the
subtitles or scale the timeline.
I have not tested this software on other systems than Linux (Fedora Core 2).
But since this is pure Ansi-C, it should not be a problem to compile it on
other systems.