"Legitimate companies" are not constrained to your personal "business hours on business days". Telemarketers and debt collectors per their Federal laws share the same daily thirteen hour period, which begins at 08:00 in your time zone. No "Sunday blue laws" are found. Your state law may trim off a few hours or days, and even then it may depend on both the call purpose and the dialing method. You are welcome to cite whatever conflicting law of which you were so certain.