Wash my mouth with soap and water, but there was a letter in Running Fitness a few months ago about a chap who works a 10 day week : 2*12hr days (6am-6pm) , 2*12hr nights (6pm-6am) then six days off.
(Sounds good to me personally!)
There was a longish reply but the gist was you change a 7 day training plan to suit a 10 day work pattern.
Key points made were:
Train harder on days off
In this case rest 1 of the 6 off days
Fit in hard sessions on days off : intervals,tempos
Do the other sessions on free days left: long easy runs,steady mid length runs.
Also on the 4 work days,try and run twice even if its a 15 minute freshen up.
(sometimes when I'm limited in time I do a 2 mile run flat out,changed,back and showered in less than 30 mins)
Having never worked shifts,although my old boss thought 7am to 9pm was normal, I hope this helps.