[3] RFC 1459 - Internet Relay Chat Protocol, , https://tools.ietf.org/html/rfc1459#section-4.3.4
[1] RFC 1459 - Internet Relay Chat Protocol, , https://tools.ietf.org/html/rfc1459#page-52
[2] RFC 1459 - Internet Relay Chat Protocol, , https://tools.ietf.org/html/rfc1459#page-54
[5] RFC から読めない IRC, https://yoshino.tripod.com/73th/data/irccode.htm#ctcp_application_time
[6] RFC 2812 - Internet Relay Chat: Client Protocol, , https://tools.ietf.org/html/rfc2812#section-3.4.6
[7] RFC 2812 - Internet Relay Chat: Client Protocol, , https://tools.ietf.org/html/rfc2812#page-51
[4] `server-time` Extension - IRCv3, IRCv3 Working Group, https://ircv3.net/specs/extensions/server-time