Taylor Swift, Calvin Harris
Taylor Swift and Calvin Harris celebrated their first anniversary together on 6 MarchREUTERS/Danny Moloshok; Anthony Harvey/Getty Images

It's already been a year since Taylor Swift and Calvin Harris started dating. The two decided to keep things simple and cute as they celebrated their one-year anniversary on 6 March.

Harris kicked things off with a "one year cake" as he referred to it on Snapchat and then presumably gifted her a heart-shaped locket with the numbers "3.6.15", engraved on it. Swift posted a picture of the locket on her Instagram account with the caption: "One year down!"

3.6.15 One year down! ❤️

A photo posted by Taylor Swift (@taylorswift) on

Swift and Harris have been enjoying their romance this past year and have been spotted together at events around the globe after they hit it off at the 2015 Brit Awards.

During an interview with a UK radio station in July 2015, Harris stated that he was "insanely happy" with Swift and recently posted a picture of her accepting her Grammy for best album of the year with the caption: "Congratulations to my beautiful girlfriend."

The DJ-producer does not want to mix business with pleasure, however. He recently turned down an opportunity to work with the New Romantics singer and is in talks with Beyonce instead.

His decision is probably based on prior experience. In 2014 Harris had collaborated with then-girlfriend Rita Ora on a number of tracks but blocked her from releasing any of them after the couple broke up.