A rapid decrease in the brightness of the sky will alert you and that totality is near. Once the darkness descends, you will know it is safe to take your glasses off and look at the totality. It is extremely important to remember that only during complete totality you might look at the Sun without our Solar Eclipse Glasses. Never look directly at the partial phases of the eclipse without our Solar Eclipse Glasses.
Even though the total part of the eclipse will last about 2 minutes, it will seem to go by much faster. Before you know it, the Sun will peek around the Moon again and will be time to put those Solar Eclipse Glasses back on.
So when does it begin and end? That depends on where you are. The eclipse occurs in mid-morning in the western US. In the middle of the country, the eclipse happens around noon. Finally, if you’re in the eastern U.S., watch the eclipse in the early afternoon.