There’s nowt funnier than folk if the gaffer was cutting back the hours to reduce cost these guys would be wanting to max out their hours on a daily basis and moaning about the drop in wages
Chill out lads, It’s only 3 times a week and if your lucky you get to sit down for 9 hours a day with a 45 minute break, two if you are good! 
I don’t understand the problem 
The last company I worked for (own account) I was told at the interview I would be salaried for a 40 hour week, however as it was a truck driving job I realised that due to various factors outside my or my bosses control I may well on occasion have to do more than the requisite 8 hours a day. My current job is general haulage, at the interview I was told I will probably be doing close to max hours, but as it’s general haulage it didn’t really need saying, having a loose understanding of the drivers hours (part of my job as I’m led to believe) I took this to mean I will probably have to do 15 hour days and that also means I might only get 9 hours off between shifts. As I wanted to be a proper truck driver, I decided that this is quite reasonable (as well as industry practice), so I shook the gaffers hand and accepted the job.
However if any of the the above jobs changed the hours without much notice or suitable recompense, “due to the needs of the business” that phrase is in yours terms & conditions too, then I’d seek other employment at the earliest opportunity.
when i turn up for a job,i do whatever is needed…if it`s a 15 hour shift,then so be it.however,when i go to bed,my phone goes on silent mode,and i have as much sleep as i need.
there are no alarm clocks in my life 