UnixMillisecondTime is a millisecond timestamp starting from the Unix epoch.
type UnixMillisecondTime uint64
func UnixMillisFromTime(t time.Time) UnixMillisecondTime
UnixMillisFromTime converts a Time value into UnixMillisecondTime.
func UnixMillisNow() UnixMillisecondTime
UnixMillisNow returns the current date/time as a UnixMillisecondTime.
func (t UnixMillisecondTime) IsDefined() bool
IsDefined returns true if the time value is non-zero.
This can be used to treat a zero value as "undefined" as an alternative to using a pointer, assuming that the exact beginning of the Unix epoch itself is not a valid time in this context.