Traffic Lights Project

I want to add an extra feature on my project but i am insure as how to go about it.
id like my circuit to have an evening and a normal mode.
So for example the traffic lights E/W during rush hour will have a longer green.
Im in the process right now of building a digital clock as my input, but after that im stumped.

My traffic lights are driven by a 7493 MOD 16 counter and a bunch of basic gates

I will post my schematic in the morning if you guys have any ideas please let me know.

You need to decode the counter to provide the light phases that you want.
For example,

N/S E/W
R G (6) [7]
R Y
R R
G R (6) [5]
Y R
R R

then repeat

G = Green, R = Red. Y = Yellow

N/S = north - south road, E/W = east west road

The numbers indicate the number of counts that the combination is on for. No number means 1 count.
The numbers in [] are the rush hour case.

Note that there are 16 lines.