The Chasom Sofer writes (in tsuva 59, I just don't remember which volume)
that one should shave for Shabbos during the three weeks even if one
doesn't shave for work during the week. While not everybody follows this
ruling, my friends and I feel that it would be a real bizoyoin, disrespect,
to Shabbos if one shaved for work and not for Shabbos.