Any elector enrolled as a member of the Republican Party shall be eligible to vote in primaries ... [Connecticut Republican State Central Committee Rules and Bylaws. Article V, Section 1. (a)]

Tuesday 26 April 2016 (presumably): Connecticut Primary. Hours 6:00a-8:00p EDT (1000-0000 UTC). Delegate Selection: Winner-Take-Most Primary. Voter Eligibility: Closed Primary.

Primary
Source: Connecticut Secretary of State.
Status: Official. Retrieved: Saturday 25 June 2016.
Included in Nationwide vote.

Tuesday 26 April 2016 (presumably): 25 of Connecticut's 28 delegates to the Republican National Convention are pledged to presidential contenders in today's Connecticut Presidential Primary. [Article I, Section 17]

• 15 district delegates are to be allocated to presidential contenders based on the primary results in each of the 5 congressional districts: each congressional district is assigned 3 National Convention delegates and the presidential contender receiving the greatest number of votes in that district will receive all 3 of that district's National Convention delegates. [Article I, Section 17. (b)]
• 13 at-large delegates (10 base at-large delegates plus 0 bonus delegates plus 3 RNC delegates) are to be allocated to presidential contenders based on the statewide primary vote. [Article I, Section 17.(a)]
• If one candidate receives a majority of the statewide vote (more than 50%), that candidate is allocated all 13 of the at-large delegates.
• If no candidate receives a majority of the statewide vote, each presidential candidate receiving 20% or more of the statewide vote shall be allocated delegates accordingly based on their percentage of the vote total of those candidates who met the 20% threshold. Round fractional proportions of a delegate to the nearest whole number. If rounding results in too few delegates being allocated, the candidate receiving the most votes receives an additional delegate. [Article I, Section 17.(g)] (no mention of what to do if too many delegates are allocated due to rounding)

Primary
Source: Connecticut Secretary of State.
Status: Official. Retrieved: Saturday 25 June 2016.

CD1: Winner-take-all for Trump.
CD2: Winner-take-all for Trump.
CD3: Winner-take-all for Trump.
CD4: Winner-take-all for Trump.
CD5: Winner-take-all for Trump.
Statewide: Trump, having received 50%+ of the statewide vote, wins all 13 delegates.

The 3 party leaders, the National Committeeman, the National Committeewoman, and the chairman of the Connecticut's Republican Party, will by virtue of their position, attend the convention as pledged delegates.

The delegates ... shall be committed ... unless released by the candidate, shall vote for the candidate on the first ballot, and shall not change their vote during the course of that ballot. [Article I, Section 17 (a)]

Circa May 2016 (date not set): State Committee Meeting. Presidential candidates submit slates of registered Republicans to serve as National Convention Delegates according to the results of the primary. The slates require the approval of the State Committee. [Section 17. (d)]

23 January 2015: Senator Joe Markley (Republican) introduced SB 610. This bill would move the Presidential Primary from the last Tuesday in April to the 1st Tuesday in March.

23 January 2015: Senator Michael A. McLachlan (Republican) and Representative Richard A. Smith (Republican) introduced SB 599. This bill would move the Republican Presidential Primary from the last Tuesday in April to the 1st Thursday in March. The Democratic Presidential Primary would continue to be held on the last Tuesday in April.

8 April 2015: Media reports indicate the Republican Party is considering using a caucus in 2016.