Got it sorted! Thanks.

def notify_timer(self, timer, when, timername, *args, **kwargs):
    if timername=='buytimer':
        self.buy_stocks()
    if timername=='selltimer':
        self.sell_stocks()

But it's still not working. Any ideas?

The timers reference had some obvious errors, it's meant to be this:

def notify_timer(self, timer, when, *args, **kwargs):
    if timername=='buytimer':
        self.buy_stocks()
    if timername=='selltimer':
        self.sell_stocks()

OK, so I tried this:

    self.add_timer(
        when=bt.Timer.SESSION_START,
        weekdays=[self.params.buy_day],
        weekcarry=True,
        timername='buytimer',
        )

    self.add_timer(
        when=bt.Timer.SESSION_START,
        weekdays=[self.params.sell_day],
        weekcarry=True,
        timername='selltimer',
        )

and then referred to these timers here:

def notify_timer1(self, timer1, when, *args, **kwargs):
    if timername=='buytimer':
        self.buy_stocks()

def notify_timer2(self, timer2, when, *args, **kwargs):
    if timername=='selltimer':
        self.sell_stocks()

Is this what you mean? Something's not quite working.

I have a question about timers. I want to create two timers, one to initiate some sell activities on a Monday and another to initiate buy activities on a Wednesday. I understand how to create two timers, but how do I associate each timer with a different activity/function?