I have a list that has a column calculated based on another column. [Reference Month] > option type (JAN/15, FEV/15, MAR/15, ..., JAN/16, FEV/16, MAR/16, ..., JAN/17, FEV/17, MAR/17, ...) [Reference Year] =YEAR([Reference Month]) Until some time ago this formula was working normally. But every item included it returns the year 2017 to the Reference Year column, even selecting months of 2015 or 2016. And many items that were previously correct, have Reference Month 2015 and 2016, but now are with Reference Year 2017. How do I solve this? Is there any other way?