DateTime Conversion and Updating Dictionary

Hi,

I have a requirement to update a field in list of dictionary items something like: 

Dictionary

id: 1

name: abc

date: "2018-11-07T11:46:28.9084403-05:00"

Dictionary

id: 1

name: abc

date: "2018-11-07T11:46:28.9084403-05:00"

This dictionary is currently in local variable local!dict, The requirement is to update the date field from string to datetime. 

I am currently using a foreach  loop with items: local!dict, expression: {id: fv!item.id, name: fv!item.name, date: rule!somerule(fv!item.date)}.

I have a rule to split the string with -,T,: saving into x ,and using datetime(x[1],x[2]....) something like that.

My 2 concerns here are Is there any better way to do the following: 

1. How can we update a particular field in dictionary items?

2. Which is the best way to convert this string to date time?

Thank you,

Yeswanth.