Converting date string to Date object

[devirtua]

Hi,
I want to validate json string received from client, and also convert date strings to the date objects in the ajv.
First part is ok, but i have doubt for the second part. What i do is:

export const DateStr = {
  $async: true,
  type: "string",
  perform: ["str-to-date"],
} as const;

Converting date string to the date object via custom written keyword.

Is it correct way to do this?