Format array of date_time in hash during hash to json conversion

so I have a class whose hash representation looks like this. {"dateTime"=>[1484719381, 1484719381], "dateTime1"=>[1484719381, 1484719381]} The dateTime here is is a unix formatted dateTime array.

I am trying to convert this hash to an equivalent of json_string for which I am using hash.to_json. Is there any way through which I can modify the format of date_time when calling to_json. The resulting json should look like this

'{"dateTime1":["2017-01-18T06:03:01+00:00","2017-01-18T06:03:01+00:00"]}'

Basically I am looking for an implementation that can be called during hash.to_json.

You cannot make this part of Hash#to_json without damaging that method dramatically because:

• You would need to manipulate the #to_json for multiple other classes
• Those are Integers which is valid JSON and changing this would be awful
• That is not the string representation of a Time object in Ruby so you need to string format it anyway

Instead you would have to modify the Hash values to represent in the desired fashion e.g.

h= {"dateTime"=>[1484719381, 14848723546], "dateTime1"=>[1484234567, 1484719381]}
h.transform_values do |v| 
  v.map do |int| 
    Time.at(int, in: '+00:00').strftime("%Y-%m-%dT%H:%M:%S%z")
  end 
end
#=> {"dateTime"=>[
#       "2017-01-18T06:03:01+0000", 
#       "2440-07-15T05:25:46+0000"], 
#    "dateTime1"=>[
#       "2017-01-12T15:22:47+0000", 
#       "2017-01-18T06:03:01+0000"]}

You could then call to_json on the resulting object to get your desired result.