Function get_time_bar_start 

pub fn get_time_bar_start(
    now: DateTime<Utc>,
    bar_type: &BarType,
    time_bars_origin: Option<TimeDelta>,
) -> DateTime<Utc>

Returns the time bar start as a timezone-aware DateTime<Utc>.

Panics

Panics if computing the base NaiveDate or DateTime from now fails, or if the aggregation type is unsupported.