user input for start time and end time.
Dates input format, "%Y-%m-%dT%H:%M:%S
st = 2018-10-10T00:00:00
et = 2018-03-30T23:59:59
after conversion it should look like:-
st1 = 2018-10-01T00:00:00 --> first day of month
et1 = 2018-06-31T23:59:59 ---> last day of month
I find arrow module most efficient for this kind of purpose.
import arrow
st = "2018-10-10T00:00:00"
et = "2018-03-30T23:59:59"
first_day = arrow.get(st).floor('month')
last_day = arrow.get(et).ceil('month')
print(first_day)
print(last_day)
# output
2018-10-01T00:00:00+00:00
2018-03-31T23:59:59.999999+00:00