The three weeks from the fast of the 17th of Tammuz (SUNDAY!) through the fast of Tisha B’Av are traditionally somber times of mourning. There are several restrictions, including hair cutting and making shechechiyanu, that start then. As we get closer to Tisha B’Av, they instensify.
Here‘s a good link to a source for an overview of the laws (Ashkenazic). If you know of an online Sefardic source, please let me know!
So time to get (and give) those haircuts today!