http://www.fourmilab.to/documents/calendar/
1 Nisan 5765 = April 10, 2005 (Sunday)
Exactly. And the day before, 29 'Adar II 5765 (4/9/05) was Shabbat HaChodesh on which the haftarah from Ezekiel displaced the one from I Samuel you mentioned, exactly as I said.
Unless Nisan 1 falls on Shabbat, its only Torah reading is the same as for any other Ro'sh Chodesh (Numbers 28:1-15), with no haftarah.