| From | To | Comment |
| 2001-04-30 | 2003-03-31 | Start of operations on 1999-04-01 without TPL.START key. Rule sets cover FORS1 aera from 2001-04-30 on, when TPL.START is available. Spectroscopic calibrations are taken as 3 flats and 1 arc in different templates. |
| 2003-04-01 | 2006-10-23 | Spectroscopic calibrations are taken as 5 flats and 1 arc in different templates. |
| 2006-10-24 | 2009-04-01 | From 2006-10-24 on spectroscopic calibrations are taken with 5 flats and 1 arc in a combined template. On 2007-04-01 the TEK detector was replaced a blue-sensitive mosaic. On 2008-04-01 the imaging calibration plan was modified by using Stetson standard stars instead of Landolt standard stars. The rule set covers all changes. FORS1 operations terminated on 2009-03-31. |