According to the Noam Elimelech on parashath B'ha'alot'cha, when we perform a time-bound mitzwah we should have in mind that the mitzwah accompany us throughout the year. The mitzwah should be with us always. We are always involved in the mitzwah the whole year.
This was good news personally as I just realized that I feel much closer to HaShem during my tefillah when I have my tefillin and talit on. Now I can be wearing them all day, even when I'm not.