'Given a dt, returns the next close.
Parameters
dt: pd.Timestamp
The dt for which to get the next close.
Returns
pd.Timestamp
The UTC timestamp of the next close.'

def next_close(self, dt):

    idx = next_divider_idx(self.market_closes_nanos, dt.value)
    return pd.Timestamp(self.market_closes_nanos[idx], tz='UTC')
