Yesterday was the 90th anniversary of the end of World War I and the beginning of our own time.

WSJ: Goodbye to All That

Allegiant can fly the bigger, 150-seat planes because it only operates most of its routes two to four times per week, employing many part-time staffers to help move tourists at the beginning and end of each weekend.

FORBES: Magazine Article

You will be able to produce more throughout the entire week, rather than taking valuable time to rev up at the beginning and wind down at the end.

FORBES: Three Ways to Get the Most out of Your Five-Day Work Week

Mainly because only one person can talk at a time, necessitating such old-movie behaviors as having to say "over" at the beginning and end of a sentence.

FORBES: Walkie-Talkie Mobile Phones