With Daylight Saving Time upon us this weekend, two national restaurant chains are helping us get through it. Denny’sand Dunkin’ are both giving away free coffee. Dunkin’s deal is a free hot or cold beverage between March 12th and 18th via Grubhub when you place a $15 order. As for Denny’s, The chain will offer Denny's Rewards members a free cup of Denny’s Signature Diner Blend coffee on March 13 between 6 a.m. and 2 p.m. local time. The coupon will show up in customers' digital wallet and is valid in-store only.