## Is your feature request related to a problem?

Compare year to date
![image](https://user-images.githubusercontent.com/1727427/101010122-8044ed00-3562-11eb-8be1-8462250ef97a.png)

With last 90 days [(link)](https://app.posthog.net/insights?display=ActionsBar&events=%5B%7B%22id%22%3A%22%24pageview%22%2C%22name%22%3A%22%24pageview%22%2C%22type%22%3A%22events%22%2C%22order%22%3A0%2C%22math%22%3A%22total%22%7D%5D&shown_as=Lifecycle&actions=%5B%5D&properties=%5B%7B%22key%22%3A%22%24current_url%22%2C%22value%22%3A%22https%3A%2F%2Fposthog.com%22%2C%22operator%22%3A%22not_icontains%22%2C%22type%22%3A%22event%22%7D%2C%7B%22key%22%3A%22id%22%2C%22value%22%3A71%2C%22type%22%3A%22cohort%22%7D%5D&interval=week&date_from=-90d)
![image](https://user-images.githubusercontent.com/1727427/101010537-9f437f00-3562-11eb-8e9f-a7e75f0018f5.png)


## Describe the solution you'd like



## Describe alternatives you've considered



## Additional context



#### *Thank you* for your feature request – we love each and every one!

posthog/queries/lifecycle.py
if period == "hour":
        return "hour"
    elif period == "day":
        return "day"
    elif period == "week":
        return "week"
    elif period == "month":
        return "month"
    else:
        raise ValueError(f"Period {period} is unsupported.")
class LifecycleTrend:
    def _serialize_lifecycle(self, entity: Entity, filter: Filter, team_id: int) -> List[Dict[str, Any]]:
        period = filter.interval or "day"
        num_intervals, prev_date_from, date_from, date_to, after_date_to = get_time_diff(
            period, filter.date_from, filter.date_to, team_id
        )
        interval_trunc = get_trunc_func(period=period)
        
        filter._date_from = prev_date_from.isoformat()
        filter._date_to = after_date_to.isoformat()
        filtered_events = Event.objects.filter(team_id=team_id).filter(filter_events(team_id, filter, entity))
        event_query, event_params = queryset_to_named_query(filtered_events, "events")
        earliest_events_filtered = Event.objects.filter(team_id=team_id).filter(
            filter_events(team_id, filter, entity, include_dates=False)
        )
        earliest_events_query, earliest_events_params = queryset_to_named_query(
            earliest_events_filtered, "earliest_events"
        )
        with connection.cursor() as cursor:
            cursor.execute(