The Ages of the Sun:

These lasted from the first rising of the Sun until present day. There were four Ages recorded:

The First Age of the Sun (The Elder Days)
The Second Age of the Sun (Sometimes counted in the Elder Days)
The Third Age of the Sun
The Fourth Age of the Sun (The Dominion of Men)

More information can be found under the individual entries for each of the Ages, under Events in Middle-Earth or Timeline for the History of Middle-Earth.