(1) Are you aware that there are no Lectionary listings for the First Sunday after Christmas, which falls on December 31, 2017? The Lectionary passes directly from December 25 to January 1. Selecting December 31 in the calendar causes January 1 to be displayed instead.
(2) Are you aware moreover, that for January 1, only the New Year's Day set of lessons appears? The Revised Common Lectionary also has a set of lessons for the Feast of the Holy Name, which falls on the same date. I would suggest that if you are unable to post more than one set of lessons per date, the Holy Name is more likely to be useful than New Year's Day for liturgical planning.
(3) Is there any access to the Lectionary apart from selecting a calendar date?