Pentaho Kettle: Transforming two Unix datetime columns into one - json

Question

I am trying to use Pentaho Kettle to read the Json file with the structure below and insert the data into the DW (Redshift).
{
"_id": {
"_data": "11111111111111"
},
"operationType": "insert",
"clusterTime": {
"$timestamp": {
"t": 1599495064,
"i": 1
}
},
"ns": {
"db": "abc",
"coll": "abc"
},
"documentKey": {
"_id": {
"$uuid": "abcabcabcabcabcabc"
}
},
"fullDocument": {
"_id": {
"$uuid": "abcabcabcabcabcabc"
},
"orderNumber": "1234567",
"externalOrderId": "12345678",
"orderDateTime": "2020-09-11T08:06:26Z[UTC]",
"attraction": "abc",
"entryDate": {
"$date": 1599523200000
},
"entryTime": {
"$date": 1599472800000
},
"requestId": "abc",
"ticketUrl": "abc",
"tickets": [
{
"passId": "1111111",
"externalTicketId": "1234567"
},
{
"passId": "222222222",
"externalTicketId": "122442492"
}
],
"_class": "abc"
}
}
As we see above both columns "entry_date" and "entry_time" are in Unix format. I need to somehow take the date component from "entry_date" and the time component from "entry_time" and transform both into a concatenated unique field that will give me the following output: "GMT: Monday, September 7, 2020 4:11:04 PM".
Also I would like to achieve the same for the field "orderDateTime" - is there any way I could use Pentaho to transform that into the same format as the above "GMT: Monday, September 7, 2020 4:11:04 PM"?
Below you can see how the 3 fields above ("entry_time", "entry_date" and "orderDatetime") are currently set up for the "Select Values" step. From there I would then take the data into the DW with the Table Output step as seen in the illustration below. Any help is appreciated.