HSMP or Tier 1 date to enter in Points based calculator

[vishnu123]

https://www.points.homeoffice.gov.uk/gu ... R_502_HELP

If you are applying under Tier 1 (General) of the points-based system this must be on or after 29 February 2008. If you first successfully applied under the Highly Skilled Migrant Programme (HSMP), Self Employed Lawyers concession or the Writers, Composers and Artists category and you are applying under Tier 1 (General) enter 29 February 2008.

I am planning to extend my existing Tier 1 visa now. I have a HSMP approval letter dated Dec/2007 later converted to Tier 1 on Oct/2009.

Question In Points based calculator :
Enter the date of your first successful Tier 1 application.

Now what date should I enter for the above question??

Dec/2007 or Oct/2009 or 29/Feb/2008 ??