It seems like you’re trying to set the value in a column called “january” to zero for all rows. Is that really what you want to do? If so then try to remove the quotes around “$date”. It shouldn’t be quoted because it’s a column name.
Also, note that if $date would come from a user then this code snippet would be susceptible for SQL injections. Never use user input directly in a query. Verify it / escape it / use parameters instead.