As you may already know, Date field for API have to be filled in UnixTimeStamp.
The correct format is to express timestamp in seconds (10 characters - Epoch Timestamp)
📌Please use this useful tool for conversion and actual date check.
📌Keep in mind that 13 characters timestamps are in milliseconds and are not supported.
For more info about how to set it, take a look here.
🔎 What's next?