Does the column only contain the year?
Excel stores dates as numbers behind the scenes, so converting an excel column containing only a year value to a date will not result in a date field of the first day of that year. (If you were to convert the year column to a short date inside of Excel you would actually get the same results.)
You could create a calculated field inside of Tableau that will do the conversion you are looking for. Something like:
Date('1/1/' + str([year]))
Thanks, Daniel - so you think its best to make sure the year is formatted as a date, right? if i don't it just has a # sign by it...
Apologies for being ignorant - VERY new at this
No, leave the year field as a number.
The Str() function in the calculated field you are going to create will convert the number to a string so that it can be combined with the '1/1/' part in order to create a string that looks something like '1/1/2001' and then the Date() will convert that string into a Date. Then use the calculated field instead of the year field wherever you had planned to use the year.
Hope this helps!