How to increment Index of type Date

I am trying to increment the index by 1 for the following array:

Date          High
2017-02-01    253.20 
2017-02-02    252.42
2017-02-03    252.18
2017-02-06    257.82
2017-02-07    260.00

I know that we can increment date by usingtimedelta(days=1) but this will generate a date which my array may not have. So is there any way to increment the index?

and after incrementing, how can i get the value for that incremented index?