What important announcement is made at the national conventions in July and August?

Important decisions like the selection of presidential and non presidential candidates are taken at the national convention.

Explanation:

Conventions settle a party's decision for presidential and vice presidential candidates. To turn into the presidential chosen one, a competitor regularly needs to win a greater part of agents. This normally occurs through the gathering's primaries and assemblies.

The proper motivation behind such a convention is to choose the gathering's chosen one for President, just as to embrace an announcement of gathering standards and objectives known as the stage and receive the principles for the gathering's exercises, including the presidential designating process for the following political race cycle.