This song was originally sung by the band Smashing Pumpkins 
The chords is in Standard tuning.:) Enjoy! 
G      D       Cadd9 
Today is the greatest 
Day I've ever known 
G      D       Cadd9 
Can't live for tomorrow, 
Tomorrow's much too long 
G      D       Cadd9 
I'll burn my eyes out 
G      D       Em 
Before I get out  
Cadd9  G   Em 
I wanted more 
Cadd9  G   Em 
Than life could ever grant me 
Cadd9  G   Em 
Bored by the chore 
Cadd9  G   D 
Of saving face 
G      D       Cadd9 
Today is the greatest 
Day I've never known 
G      D         Cadd9 
Can't wait for tomorrow 
I might not have that long 
G      D        Cadd9 
I'll tear my heart out 
G      D  Em 
Before I get out 
Cadd9  G   Em 
Pink ribbon scars 
D 
That never forget 
Cadd9  G   Em 
I tried so hard 
D 
To cleanse these regrets 
Cadd9  G   Em 
My angel wings 
D 
Were bruised and restrained 
Cadd9  G   D 
My belly stings 
G      D 
Today is 
G      D 
Today is 
G      D 
Today is 
    Cadd9    D 
The greatest day 
  G        D      Em 
I want to turn you on 
  G        D      Em 
I want to turn you on 
  G        D      Em 
I want to turn you on 
G              Em 
I want to turn you 
G      D       Cadd9 
Today is the greatest 
G      D       Cadd9  Em  
Today is the greatest day 
G      D       Cadd9  Em 
Today is the greatest day 
G      D       Cadd9     G (strum the last chord slowly) 
That I have ever really known