def last_year(self): return self[(self.time > last_year()) & (self.time < now())]
def last_week(self): return self[(self.time > last_week()) & (self.time < now())]
def last_month(self): return self[(self.time > last_month()) & (self.time < now())]
def yesterday(self): return self[(self.time > yesterday()) & (self.time < now())]