The 28MHz SWL Contest will be in the second full weekend of December, so this year on 9 and 10 December. This is the same weekend of the ARRL 10Meter Contest.
For the rules you may visit the website of the VERON, SWL section: https://www.veron.nl/vereniging/commissies-en-werkgroepen/nl-commissie/swl-contesten-nlc/ .
Wishing you lots of success in this and other (SWL) contests!
73, Ruud Ivens, NL290, SWL Contest Manager VERON.