import pandas as pd


orders = pd.DataFrame(
    {
        "order_id": [1001, 1002, 1003, 1004],
        "ordered_at": [
            "2026-06-01 09:30",
            "2026-06-02 14:00",
            "not recorded",
            "2026-06-04 08:15",
        ],
        "shipped_at": [
            "2026-06-01T17:45:00+08:00",
            "2026-06-02T07:10:00Z",
            "bad timestamp",
            "2026-06-04T12:00:00+08:00",
        ],
    }
)

orders["ordered_at_raw"] = orders["ordered_at"]
orders["shipped_at_raw"] = orders["shipped_at"]