Is this shift pattern legal to do

Work 4days 1 day off work 2 days then again 1 day off then back in for 4 days then back on normal shift patten 4on 4off any info thanks

Oh dear!

Shall we have a poll ?
I say yes !

Happy sole:
Work 4days 1 day off work 2 days then again 1 day off then back in for 4 days then back on normal shift patten 4on 4off any info thanks

On what day is the first of those days?
What weekly rest was taken just prior to the first 4 days work?

Giving us more info like this would help …

Off mon tue wed thu
Work fri sat sun mon = the first 4 days of your quote
off tue
work wed thu
off fri
work sat sun mon tue = the last 4 days of your quote
off 4
work 4
etc etc