Add unavailability details for a employee

Example

{   
    "employee": 1,
    "start": {
        "timestamp": 1657001675
    },
    "end": {
        "timestamp": 1657001676
    },
    "strComment": "Here is a note for some unavailability",
    "recurrence": {
        "FREQ": "WEEKLY",
        "INTERVAL": 2,
        "BYDAY": "MO"
    }
}