The map shows the dates of the primaries and caucuses scheduled so far. The primary dates are chosen by the state legislatures. The caucus dates are chosen by the parties. Some of them haven't made their choices yet, so we have made educated guess based on previous years. Nevertheless, there may be changes as time goes on.

The legend is at the right, where seven intervals are distinguished. The number on each state is how many electoral votes its has.

The Republican National Committee has laid down four rules that must be obeyed. The penalty for not obeying the rules is a loss of most of the state's delegates. Here are the rules.

1. No primaries or caucuses in January
2. Only Iowa, New Hampshire, South Carolina, and Nevada may go in February
3. Primaries and caucuses before March 15 must divide delegates proportionally to the vote
4. On or after March 15, states may choose proportional representation or winner-take-all as they prefer

The Democrats do not always hold their events on the same days the Republicans. The map shows the Republican dates. But if you put your mouse cursor on a state, the pop-up box shows both dates if they differ.