- Question: [Tuesday, 4th Kisleiv 5782]
I have heard a number of times that you can be more lenient with Rabbeinu Tam Tefillin, to put them on past sunset or even past nightfall prior to the time of Rabbeinu Tam? Is this correct?
This is incorrect. Initially one must wear even Rabbeinu Tam Tefillin before sunset, and at the very least before nightfall [Bedeived, if for whatever reason he did not wear before sunset]. After the nightfall of the Geonim arrives, it may no longer be worn.
Explanation: It is forbidden to wear tefillin at night, and we are initially stringent to wear them before sunset, and only in the case of Bedieved do we allow putting them on until nightfall. In this regard one must follow the nightfall of the Geonim, which is the accepted ruling today both for leniency and stringency. The fact that Rabbeinu Tam is of the opinion that nightfall is later does not affect in any way the law regarding wearing Tefillin of Rabbeinu Tam. The dispute regarding tefillin of Rashi versus Rabbeinu Tam and the dispute regarding the time of night of the Geonim versus Rabbeinu Tam are two completely different disputes which have nothing to do with each other, and while regarding the dispute of Rashi versus Rabbeinu Tam tefillin we are stringent to also put on Rabbeinu Tam, regarding the dispute of the time of night we are completely lenient like the Geonim. Accordingly, there is no room to be lenient to put on tefillin of Rabbeinu Tam past nighttime of the Geonim [which is the regular time of night listed in all calendars], and transgress the prohibition against wearing tefillin at night. To what is this similar? The same way that nobody would argue to say that the Shabbos prohibitions which follow the opinion of Rabbeinu Tam may be transgressed until the time of Rabbeinu Tam arrives on Erev Shabbos [i.e. setting up a Mechitza Hamateres on Shabbos; Squeezing inedible fruits; immersing on Shabbos if husband not in city; ], so too here the two should not be connected.
Sources: See Piskeiy Teshuvos 30:2; Yisrael Vehazmanim [Horpanez] 3 [is lenient to permit wearing until Tzeis of Rabbeinu Tam even Tefillin of Rashi although negates initially doing so even with Tefillin of Rabbeinu Tam, and for us that we hold like Geonim, this would apply even Bedieved]; See regarding the prohibition of wearing tefillin after nighttime: Admur 30:1; Michaber 30:2; Eruvin 96a and Menachos 36b