Sending an invoice sets the wrong "sent date"

[justsomebody42]

Steps to reproduce the issue

Create a draft invoice.
Wait at least one day.
Go to invoice detail screen
Press "mark as sent"

Expected result

Sent date of invoice matches the date of the day, when the button "mark as sent" has been pressed.

Actual result

Sent date of invoice matches the created date.

System information (Akaunting, PHP versions)

Akaunting Version 1.3.17

Additional comments

[denisdulici]

That's right, it uses the created_at field as there is no sent_at field.

[justsomebody42]

Wouldn't it be better to use the current date?
The purpose for drafts is to create them prior to sending them and probably send them days later.
I would assume that the date is correct, if an invoice is sent by akaunting itself, but as the templates are currently unusable for me, I need to send them separately and hit the "mark as sent" button, when I did.