>>> lst = [1580086800000,1580097600000,1580101200000,1580112000000,1580140800000,1580148000000,1580151600000,1580169600000,1580173200000,1580194800000]
>>> output = []
>>> for i in lst:
...     tmp_i = str(i)[:-3]
...     new_ts = datetime.fromtimestamp(float(tmp_i))
...     output.append(new_ts)
...
>>> print(output)
[datetime.datetime(2020, 1, 27, 2, 0), datetime.datetime(2020, 1, 27, 5, 0), datetime.datetime(2020, 1, 27, 6, 0), datetime.datetime(2020, 1, 27, 9, 0), datetime.datetime(2020, 1, 27, 17, 0), datetime.datetime(2020, 1, 27, 19, 0), datetime.datetime(2020, 1, 27, 20, 0), datetime.datetime(2020, 1, 28, 1, 0), datetime.datetime(2020, 1, 28, 2, 0), datetime.datetime(2020, 1, 28, 8, 0)]