Massachusetts 1  : Current law sets the Presidential Primary to the 1st Tuesday in March and the Partisan Primary to 7th Tuesday [20 September 2016] preceding the November General Election [The General Laws of Massachusetts, Title VIII, Chapter 53: Section 28.].
http://www.thegreenpapers.com/P16/
A Primary Election is a preliminary (nominating) election to select, when necessary, Democratic, Republican and nonpartisan candidates who will run in the General Election contests (except candidates for special district offices because they will only appear in the General Election).
http://www.mytimetovote.com/2016-Primary-Election-Dates.html
The first presidential primary election was held in 1901 in Florida, and by 1916, presidential primary laws had been passed in 26 states. More than 40 of the 50 states hold primary elections by 2005. The presidential candidates are officially and formally nominated by national party conventions. A couple of months before the national conventions meet, almost all U.S. states hold primary elections to select the party candidates.
http://aceproject.org/ace-en/topics/pc/pcy/pcy_usa
1 notification of the chosen date by December 1st of the year prior to the presidential election year.... 2  If 3  ... more than one party and those parties agree by November 1st of the year prior to the presidential election year to one date, the State shall hold the presidential primary election on that agreed-upon date.
http://www.thegreenpapers.com/P16/
Nomination procedures in the United States are unlike those of most other democratic systems. The primary election system in the strict sense, often called the direct primary election system, is used only in the U.S., and only in a few of the states.
http://aceproject.org/ace-en/topics/pc/pcy/pcy_usa
Only in some states are candidates nominated by convention. In the latter case, two-stage elections are held, with a primary election as a first stage and a run-off if no candidate has the majority in the direct primary election.
http://aceproject.org/ace-en/topics/pc/pcy/pcy_usa
Types of primary elections. As mentioned above, the primary election system varies between the US states in terms of who is entitled to vote in the party’s primary election. In open primaries, voters of the state can participate in one of the primary elections, irrespective of their party affiliation.
http://aceproject.org/ace-en/topics/pc/pcy/pcy_usa
1 a party 2  ... has voted to conduct a presidential primary ... the State shall hold a presidential primary election 3  .... The party shall deliver 4  ... notification of the chosen date by December 1st of the year prior to the presidential election year....
http://www.thegreenpapers.com/P16/
Notes: Pursuant to Nevada law, Nevada does not conduct Primary Elections to select Presidential candidates. Instead,major political parties will hold caucuses in the beginning of 2016 at dates, times, and locations that they will determine.
http://www.mytimetovote.com/2016-Primary-Election-Dates.html
2016 Primary Elections Schedule. The 2016 U.S. general election will be held on Tuesday, the 8th of November 2016. This election year will feature Presidencial Election, elections to the United States Congress.
http://www.mytimetovote.com/2016-Primary-Election-Dates.html
which states hold primary elections
Florida hold primary elections. The state that holds primary elections is Florida.