Answer:

DST

Answer	Crossword Clue
DST	Summer hours
DST	Spring-ahead letters
DST	Summer hrs.

DST	Aug. clock setting
DST	Summer time?
DST	Hrs. that end next month(!): Abbr.
DST	Clock setting (abbr.)
DST	August hrs.
DST	Wash., D.C., thoroughfare
DST	"Spring ahead" hrs.
DST	Aug. hrs.

DST	Hrs. of summer
DST	"Spring forward, fall back" syst.
DST	Apr.-to-Oct. setting
DST	Aug. hours
DST	It ends in Oct.
DST	It ends in late Oct.
DST	It starts in Apr.
DST	It starts on Mar. 11th this year

DST	Mar.-to-Nov. hrs.
DST	Ariz. hasn't observed it since 1967
DST	It lasts almost eight mos.
DST	Mar.-to-Nov. setting
DST	It ends in Nov.
DST	Much-anticipated spring thing: Abbr.
DST	"Spring ahead" abbr.
DST	Annual cause of losing an hr.'s sleep, perhaps

DST	Haw. doesn't observe it
DST	"Spring forward" letters
DST	This year, it ends Nov. 3rd
DST	Summer clock setting (abbr.)
DST	July hrs., in most states
DST	Summer setting (abbr.)
DST	Syst. of late sunsets
DST	Letters that change hands in April?

DST	Schedule-shifting syst.
DST	Hartford summer hrs.
DST	Its arrival may lead to a missed appt.
DST	"Spring ahead" syst.
DST	"Spring ahead" letters