It's the same date as they changed my status to "Approved" on my CIC account, when I called them it's been confirmed that this date was the date they sent the envelope.How do you know that Pr CARD HAS BEEN SENT ?
The agent also told me that it's the date from which I need to count 6 weeks in case I would not receive my card. After that you need to send a filled form and they will print the card in two business days and will send it again.