Oh, now I get it, they reply to "happy new year" comments. 

 ℋ𝕒p⍴𝓎 ɴҽ𝔀 𝘠℮𝑎𝚛! 

 𝕳𝖆𝖕𝖕𝖞 𝕹𝖊𝖜 𝖄𝖊𝖆𝖗!