Example of Proper Usage:

'Twitter Series C round, February 12, 2009' → 'Date Announced' → 'February 13, 2009' is correct, citation: https://blog.twitter.com/official/en_us/a/2009/opportunity-knocks.html.

Example of Improper Usage:

'Twitter Series C round, February 12, 2009' → 'Date Announced' → 'February 12, 2009' is incorrect because this was the date the round closed, rather than the date it was announced. Often a funding round will be announced after the actual date the round has closed. Citation: https://blog.twitter.com/official/en_us/a/2009/opportunity-knocks.html.