Texas Election Code - ELEC § 181.061. Conventions at which Nominations Made

(a) A political party nominating by convention must make its nominations for statewide offices at a state convention held on the second Saturday in April of the election year, except that if the Sunday after the second Saturday in April in an election year is the date of the Easter holiday, the state convention must be held on the third Saturday in April of that year.  The state convention consists of delegates selected at the county conventions held under Subsection (c).

(b) A party nominating by convention must make its nominations for offices of districts situated in more than one county at district conventions held on the second Saturday after the second Tuesday in March.  A district convention consists of delegates selected at the county conventions held under Subsection (c).

(c) A party nominating by convention must make its nominations for county and precinct offices and for offices of districts not situated in more than one county at county conventions held on the first Saturday after the second Tuesday in March.  A county convention consists of delegates selected at precinct conventions held on the second Tuesday in March in the regular county election precincts.

(d) A party by rule may limit the delegates making nominations to those from the territory from which the office sought is elected.