Timeline: by year but not specific date

Try creating a formula field that’ll convert your year to a date, and then use that field instead?

DATETIME_PARSE(
  '01 01 ' & Year, 
  'DD MM YYYY'
)

Hello! Thanks, yeah, I am starting to realize that I just need to plug in full dates even if I know they are not accurate. Thanks! 

 One thing to consider though from a museum/archival perspective (if that’s important) is you want to make clear that all those 1/1/2012 and 1/1/1998 date stamps aren’t real date stamps. If that data integrity is important and you have photos where you want to keep the actual date and not just the year, you could make this with an override setup, where Year and Date are editable fields, and they combine into a formula field. 

Something like 

IF(Year, DATETIME_PARSE(
  '01 01 ' & Year, 
  'DD MM YYYY'
), Date)

OK ​@DisraeliGears01 - this is important to me, not because I am running an official state archive or anything, but because it just doesn’t sit right with me to knowingly tag something with incorrect information. Thanks for this - I will try it.