#Bash +GNU date, 72 bytes

    for((;1`date +%d%m -d$d\day`!=12512;d++));{ x+=\ Eve;};echo Christmas $x

[Try it online][1]



  [1]: https://tio.run/##S0oszvj/Py2/SEPD2jAhJbEkVUFbNUU1V0E3RSUlJiWxMkHR1tDI1NDIOkVbW1PTulqhQts2RsG1LNW61jo1OSNfwTmjKLO4JDexWEGl4v9/AA