Consider the following:

data={{{3544128000, 80}, {3544732800, 80}, {3545337600, 80},
{3545942400, 80}, {3545942400, 160}, {3546547200, 160}, {3547152000, 0}}};

After the satisfying answers to my former question (Part 1), another issue occurred, but with the same background (List-operations only when restrictions are fulfilled):

After applying

Transpose[{#[[All, 1, 1]], 
      Total[#[[All, All, 2]], {2}]}] &[#] & /@ (GatherBy[#, First] & /@
    data)

on data (thanks to Andy Ross for the approach), I receive

{{{3544128000, 80}, {3544732800, 80}, {3545337600, 80}, {3545942400, 240},
{3546547200, 160}, {3547152000, 0}}}

which resembles to

{{x_-n*604800_, y_},...,{x_-604800_, y_}, {x_, u_},
{x+604800_, z_},{x_+2*604800_, z_},...,{x_+m*604800_, z_}}

I would like to do the following:

1. u_->y_ (Transform u_ to y_)
2. residual=(y_-u_)/(n+1) (Calculate residual of y_ and u_ and divide it be n+1)
3. {{x-n*604800_, y_+residual},...,{x-604800_, y_+residual}, {x_, y_+residual},{x+604800_, z_},{x_+2*604800_, z_},...,{x_+m*604800_, z_}} (Distribute residual to all periods from x_-n*604800 to x_)

The result in case of data will then be:

{{{3544128000, 120}, {3544732800, 120}, {3545337600, 120}, {3545942400, 120},
    {3546547200, 160}, {3547152000, 0}}}