The weekend doesn't start in Destiny until Xur has arrived.
Xur: Agent of the Nine has made his weekly stop at Destiny's Tower as expected. Xur sells Exotic weapons and armour, though weapons are not always the Year 2 versions.
Outside of weapons and curios, Xur also sells Three of Coins and Glass Neddle. Three of Coins is an item you pop before fighting bosses for a better chance at Exotic drops. Glass Needle is an item needed whenever you're re-rolling stats on your Exotic armour.
You can find Xur at the bar in Tower north. You have until 9am GMT on Sunday, March 13 before he leaves.
And here's what you can spend your Strange Coins on: