using Time of day

Because the wiki shows ${Time.Time24} as HH:MM:SS you couldn't do it just like you listed (the : is unparsable). I think if you're just looking for anything between 6 & 7 you could just do ${Time.Hour}, which returns 0-23.

So:

/if (${Time.Hour} == 6) {
/echo It's six o'clock, time to leave.
/endm
}