When are tefillin put on?

Tefillin are the arm and head boxes containing four Torah passages. Their meaning includes directing the heart and mind toward God and remembering the Exodus (Shulchan Aruch, OC 25:5). They are normally worn during weekday morning prayer; Shulchan Aruch specifically stresses wearing them for Shema and prayer (OC 25:4).

The earliest ordinary time is when daylight allows recognition of an acquaintance at four cubits, called misheyakir (OC 30:1). This is not automatically sunrise or a fixed clock time throughout the year. Consult the local timetable. Night is not the normal time for putting them on (OC 30:2).

They are not worn on Shabbat or festival Yom Tov, because those days are themselves a covenantal “sign” (OC 31:1). Chol HaMoed has a genuine difference: Shulchan Aruch prohibits wearing them, while the Rema records wearing them with a blessing said quietly (OC 31:2). Sephardi practice generally follows the former; Ashkenazi communities differ. In Israel, the prevailing custom, including among Ashkenazim, is not to wear tefillin on Chol HaMoed. For communities that wear them, Mishnah Berurah recommends doing so without a blessing because of the dispute (31:8).

A Beit Din may ask whether missing Shacharit means missing the entire opportunity. The daytime period remains the relevant time, not only the morning service (OC 30:1–2). A common mistake is assuming one Chol HaMoed practice is universal. Confirm your community’s custom rather than copying another worshipper.