If i work less than my 40 hours can my employer demand i work extra shifts to make up the 40 hours he pays?

i have a C of E that states my hours are 40 per week. I normally work Monday to Friday nights. However sometimes my work only takes 30 hours per week and i am paid a guaranteed 40 hours. Can my employer ask me to make up the missing hours by working extra shifts on saturday or sunday?If i work less than my 40 hours can my employer demand i work extra shifts to make up the 40 hours he pays?
Hourly workers are paid for their time while salaried workers are paid for their production and/or achievement of goals. You employer is well within his rights to demand you put in 40 hours of work for 40 hours of pay.If i work less than my 40 hours can my employer demand i work extra shifts to make up the 40 hours he pays?
IT DEPENDS ON UR COMPANIES POLICY, I ADVISE YOU CHECK WITH A CO- WORKER WHO IS A VETERAN IN THE COMPANY AND KNOWS THE INSIDE AND OUTS OF IT.