User talk:Platyou

I'm puzzled by two petrochemical nounes. what's the difference between BPSD(barrels per stream day)and BPCD(barrels per calender day)? if a refinery produced 10000 barrel kerosene last month(30 day),and there were 28 days on stream. IS the BPSD equal to 10000/28? and BPCD equals to 10000/30? thank you.