You can't really 'schedule' the handle_data method (it always runs every minute of trading) but you can do a simple time check to get the time. Something like this should work for you.

def handle_data(context,data):  
    """  
    Called every minute.  
    """  
    current_time = get_datetime('US/Eastern').time()  
    start_time = datetime.time(hour=9, minute=45)  
    if current_time < start_time:  
        return

    # put any code below and it will only execute AFTER the start time

Depending on what you're trying to accomplish, you can also put your logic from handle_data into another function and run that function using scheduled_function()

Josh's suggestion is a good one. More efficient and also potentially more flexible. Maybe something like this.

def initialize(context):  
    """  
    Called once at the start of the algorithm.  
    """  
    # Set the start time and stop time ( both in minutes)  
    # There are typically 390 trading minutes in a day.  
    # Also set the frequency in minutes (in this case every 5 minutes)  
    # Frequency can be set to 1 to mimic the behaviour of handle_data  
    start_time, stop_time, frequency = 15, 390, 5  
    for minutes_offset in range(start_time, stop_time, frequency):  
        schedule_function(  
            my_function,  
            date_rules.every_day(),  
            time_rules.market_open(minutes=minutes_offset),  
            half_days = True)

def my_function(context,data):  
    """  
    Do any logic here. Will be executed each time it's scheduled  
    """  
    log.info(get_datetime('US/Eastern').time())  

this is very helpful - i'm going to give these a go.

i tried to scheduled_function() but i am comparing current minute data to the previous 10 minutes and couldn't find a way to run my function every minuted with scheduled_function().

Thanks.

A condensed version of Dan's in case it might help with the particular way of thinking/learning by some. Since half_days True by default, isn't needed. Here, the 5 is changed to 1, to run every 1 minute instead of every 5 minutes. The 1 can be dropped unless planning to change it. Also 391 is needed to have 390 included in the results from range. market_close() runs one minute before market close (otherwise any orders within the function called would not execute) while market_open(minutes=390) is the route to run something at market close for gathering some sort of information for example.

def initialize(context):  
    for i in range(15, 391, 1):    # start, stop, every n minutes, where n is 1 in this case  
        schedule_function(run_this, date_rules.every_day(), time_rules.market_open(minutes=i))

def run_this(context,data):  
    # your code  

kewl. Thx.