定时运行代码相关问题？

运行的时间点 time 和 a 相关联：
第一个time21:36:40,时a=1
第二个time21:36:50,时a=2
第三个time21:36:55,时a=3
请问，代码怎么编写？

import datetime
def fun():
    l = [1, 2, 3]
    a=1     #(第一个time21:36:40,时a=1)
    #a=2     #（第二个time21:36:50,时a=2）
    #a=3    #（第三个time21:36:55,时a=3）
    for i in l:
        if i>a:
            print(i)
d=[]
while True:
    now = datetime.datetime.now()
    time = datetime.datetime.strftime(now,'%H:%M:%S')
    if time not in d and (time == "21:36:40" or time == "21:36:50" or time == '21:36:55'):
        d.append(time)
        fun()
        if len(d)==3:
            break

import datetime

def fun(i):
    l = [1, 2, 3]
    a=i+1
    for i in l:
        if i>a:
            print(i,end=' ')
    print()

d = []
times = ["21:57:00" , "21:57:01" , '21:57:02']
while True:
    now = datetime.datetime.now()
    time = datetime.datetime.strftime(now, '%H:%M:%S')
    if time not in d and time in times:
        d.append(time)
        fun(times.index(time))
        if len(d) == len(times):
            break