JSON / ASP.NET AJAX Dates support in PostgreSQL

Hello,

Is there an easy way to convert JSON data containing ASP.NET AJAX Dates into PostgreSQL timestamp?

I have this kind of JSON data:

{
"PurchaseOrder" : "4500000000",
"CreationDate" : "\/Date(1672358400000)\/",
"LastChangeDateTime" : "\/Date(1672692813062+0100)\/"
}

Warning: Note the backslash before the slashes!
According to JSON spec this is valid JSON and used by AJAX Date format.

When loading that data in Firefox, the JSON visualizer shows AJAX Date values as

"/Date(1672358400000)/"

and

"/Date(1672692813062+0100)/"

(without the backslash)

My understanding is that backslash + slash = slash in JSON strings.

How can I load this record into a table defined as:

CREATE TABLE custorder (
"PurchaseOrder" BIGINT NOT NULL PRIMARY KEY,
"CreationDate" TIMESTAMP NOT NULL,
"LastChangeDateTime" TIMESTAMP NOT NULL
)

?

Seb