| 2000 April 28 | CP Version 1 Issued |
| 2000 June 30 | CP Version 2 Issued; GTO programs and targets announced |
| 2000 July 31 | Letters of Intent Due |
| 2000 September 15 | Proposals Due |
| 2000 October 23 (week of) | Time Alloction Committee meets |
| 2000 November | Legacy Science projects selected |
| 2000 December | Approved teams established and funded |
| 2001 January (12-13) | LegSci Workshop (Pasadena) |
| 2001 April | LegSci Teams Submit Revised Observations |
| 2001 September | LegSci Observing Strategy Review |
| 2001 October | LegSci Teams Submit AORs |
| 2002 May-June | LegSci Data Plan Review |
| 2003 August | Spitzer launch |
| 2003 December | Legacy Science observations begin |
| 2004 September | Initial Legacy Science Products delivered |
| 2004 October | Initial Legacy Science Products released |
| 2004 December | GLIMPSE Legacy data release |
| 2005 April | Legacy Science Products released |
| 2005 October | Legacy Science Products released |
| 2006 April | Legacy Science Products released |
