An article released by today by the AP referred to "Eastern War Time" as a time zone. What was this and how did it come about?

by driftingphotog

The Associated Press posted their old article about the atomic bombings which contained the following phrase:

President (Harry) Truman disclosed in a White House statement at 11 a.m. Eastern War Time, today that the first use of the bomb — containing more power than 20,000 tons of TNT and producing more than 2,000 times the blast of the most powerful bomb ever dropped before — was made 16 hours earlier on Hiroshima, a Japanese army base.

It's clear to me that Eastern War Time is analogous to Eastern Standard/Daylight Time. But what is the distinction? Was this before EST/EDT was referred to as a time zone? Did it have applications in the clarity of communications between military forces on different continents? Why would this have been more effective than just using the normal time zones?

EDIT: Title typo, sorry. "An article released today by the AP"

The_Alaskan

It's a small distinction from daylight saving. The 1942 War Time Act put the United States on year-round daylight saving time, ostensibly as a way to improve production and save energy.

In February '42, White House Press Secretary Stephen Early said it was President Roosevelt's decision to call the change "war time" since "that's what it is."

The measure wasn't universally accepted. In Michigan, the state legislature voted to put the state back on normal time ─ but that meant that only state and local agencies would be put back on regular time. Federal agencies would stay on war time, and so would the city of Detroit, which asked to retain war time.