Let users set date time format

[yunjoonjung-PNNL]

Can we let users set date time format?

For example, instead of the following,

ConStrain/constrain/api/data_processing.py

Line 67 in 23c40a1

data.index = pd.to_datetime(data.index)

Can we let users specify there date format such as data.index = pd.to_datetime(data.index, format='%m/%d/%Y, %I:%M:%S %p'), %m/%d/%Y, %I:%M:%S %p is a user input somewhere? This is because sometimes pandas caused an error that can be prevented. it's also cumbersome to change the date time in Excel.