Best practice for date tagging

[Mangar]

Hello,

is there a best practice for tagging of dates. I use MP3tag and ID3v2.4 and most of my music has the year tagged as YYYY, but little by little I put the release date in the year tag. Is this recomended?

Another problem is the date tagging of remastered albums. At example, Dio's album Dream Evil was originally released at 1987-07-21, the remastered in 2013 and I tagged it this way:
YEAR 1987-07-21
ORIGYEAR 1987-07-21
RELEASETIME 2013-03-07

Other Albums I tagged this way, but I think it's wrong:
DATE 2305 (DDMM)
YEAR 2014
But this album is displayed in my UPNP-Player under 2305. It treats the date as year.