Reapeted measures Anova Tukey test in GLM

Hello,
I am running a repeated measures anova using proc glm. I am not having a problem with the anova itself, but when I do a tukey test at the end, it is giving me pairwise comparisons broken down by each trial (month). What I need is adjusted pairwise comparisons for the entire experiment eg) pairwise experiments between each treatment with all trials (months) combined.
This is what I have entered that is giving me the tukey comparisons broken down my month:

data pl;
input transect habitat M1 M2 M3;
cards;
1 1 6 19 30
2 1 1 1 13
////////////////////////////
17 3 5 28 12
18 1 0 0 8
;
proc glm data=pl;
class habitat;
model m1 m2 m3=habitat / nouni;
repeated month 3;
lsmeans habitat / adjust=tukey;
run;

The output gives me pairwise comparisons between treatments (habitat) for each month (m1 - m2 - m3 ), but I need p values for pairwise comparisons between treatments for the entire experiment (all three months).

Does anyone have any idea how I can achieve this?

Thanks,