Well, this is my first tab.
to me it sounds better done in bar chords
and im not sure if Relient K plays it Eb,
so i just did standard tuning, besides,
i cant be bothered changing the tuning most of the time
Enjoy.

Intro while the lead guitarist is playing the riff goes C, D, F, C. pretty much 
the same as the verse.
This part is also played halfway through the song, just before the second verse.

Intro:
   C (x32010@1)                D (xx0232@1)                    F (133211@1)                Ce|---------------------------------------------------------------------------| (x32010@1)B|-----8-----------8--8---6---------------8--8---6----------6--5-------------|
G|-5-----------5-------------5--------5--------------5-----------------------|
D|-------------------------------------------------------5-------------------|
A|---------------------------------------------------------------------------|
E|---------------------------------------------------------------------------|



Verse 1:
C (x32010@1)                             DYesterday, (xx0232@1)is not quite what it could've been
F (133211@1)                              CAs (x32010@1)were most of all the days before
C (x32010@1)                                      DBut (xx0232@1)I swear today, with every breath I'm breathing in
F (133211@1)                                 CI'll (x32010@1)be trying to make it so much more


Pre-Chorus:
         F (133211@1)                 G (320003@1)       ACause (x02220@1)it seems I get so hung up on the history of whats gone wrong
        F (133211@1)                  C (x32010@1)                 G (320003@1) 
And the hope of a new day is sometimes hard to see 
        F (133211@1)                G (320003@1)             ABut (x02220@1)I'm finally catching onto it, yeah the past is just a conduit
        F (133211@1)                 F (133211@1)               GAnd (320003@1)the light there at the end is where I'll be


Chorus:
                    F (133211@1)      G (320003@1)                 ACause (x02220@1)I'm on the up and uuuuuuuup, I'm on the up and uuuuuuuup
                F (133211@1)                G (320003@1)     AAnd (x02220@1)I haven't given up, given up on what I know I'm capable of
              F (133211@1)      G (320003@1)                AI'm (x02220@1)on the up and uuuuuuuup, yeah there's nothing left to prove
      C (x32010@1)                B (x2444x@1)         A (x02220@1)         G (320003@1)     FCause (133211@1)I'm just trying to be a better version of me for you
                     F(silence)
A better version of me for you


Verse 2:
      C (x32010@1)                           DTo (xx0232@1)be prosperous would not require much of me
           F (133211@1)                             CYou (x32010@1)see contentment is the one thing it entails
         C (x32010@1)                                      DTo (xx0232@1)be content with where I am and getting where I need to be
    F (133211@1)                                  CI'm (x32010@1)moving past the past where I have failed


Pre-Chorus:
        F (133211@1)               GBut (320003@1)I'm finally catching onto it
         A (x02220@1)        
Yeah the past is just a conduit
        F (133211@1)                 C (x32010@1)               GAnd (320003@1)the light there at the end is where I'll be


Chorus:
                       F (133211@1)      G (320003@1)                 AOh (x02220@1)cause I'm on the up and uuuuuuuup, I'm on the up and uuuuuuuup
                F (133211@1)                G (320003@1)     AAnd (x02220@1)I haven't given up, given up on what I know I'm capable of
              F (133211@1)      G (320003@1)                AI'm (x02220@1)on the up and uuuuuuuup, yeah there's nothing left to prove
      C (x32010@1)                B (x2444x@1)         A (x02220@1)         G (320003@1)     FCause (133211@1)I'm just trying to be a better version of me for you
                     
A better version of me for...


Bridge:
A (x02220@1)                     F (133211@1)                                  CYou (x32010@1)never cease to supply me with what I need for a good life
                                         GSo (320003@1)when I'm down I'll hold my head up high cause you're the reason why


Chorus:
                              F (133211@1)      G (320003@1)                 AYeah (x02220@1)you're why I'm on the up and uuuuuuuup, I'm on the up and uuuuuuuup
                F (133211@1)                G (320003@1)     AAnd (x02220@1)I haven't given up, given up on what I know I'm capable of
              F (133211@1)      G (320003@1)                AI'm (x02220@1)on the up and uuuuuuuup, yeah there's nothing left to prove
      C (x32010@1)                B (x2444x@1)         A (x02220@1)         G (320003@1)     FCause (133211@1)I'm just trying to be a better version of me for you
                           
I'm just trying to be a better version of me for 
C (x32010@1)    B (x2444x@1)    A (x02220@1)    G (320003@1)    Fyoooooooooooooouuuuuuuuuuuuuu (133211@1)

Outro:
e|---------------------------------------------------------------------------|
B|-6---5-----------6--5------------------------------------------------------|
G|---------5-----------------------------------------------------------------|
D|-------------5-------------------------------------------------------------|
A|---------------------------------------------------------------------------|
E|---------------------------------------------------------------------------|