Very simple relative time formatting:
> _relTime = new Intl.RelativeTimeFormat("en")
RelativeTimeFormat [Intl.RelativeTimeFormat] {}
> _relTime.format(-2, "day")
'2 days ago'
> _relTime.format(2, "hour")
'in 2 hours'
> _relTime.format(24, "year")
'in 24 years'
> _relTime.format(0, "month")
'in 0 months'