Calvin Harris - Worst Day

      The entire song uses the same 4 chords throughout repeated..

These are the four chords:

      C     B    D     C#
e|----x-----x----x-----x----|
B|----x-----x----x-----x----|
G|----9-----8----11----10---|
D|----10----9----12----11---|
A|----10----9----12----11---|
E|----8-----7----10----9----|

You should be able to easily pick up their timing and strumming pattern by listening to 
the song..

Hope this is cool- Cheers! DR~