Daylight saving is a difference of an hour, how does that relate do a date field? And timezones can be ignored when you are checking on a date to see if it is a YEAR away.

Next to that: a solution was asked, without mentioning it should be translated or anything like that. Of course you don't want hard coded messages when you have multiple languages on an instance, but where was this mentioned to be a requirement? You are making assumptions that aren't based on anything. A solution was asked and based on the given information a possible solution was given. These can (and should) be tweaked to get the perfect solution, but you are getting date/time involved and translations, that were nowhere mentioned.