Ah yes, sorry. Red Nose day is a Friday in March every two years, run by Comic Relief. This is a disparate group of (mostly) comedians, some entertainers who raise money on one specific date. Think Live Aid, but funnier and more regular. Their symbol is a red nose, which changes in style each time so - like football shirts - you can't wear the same one year after year. Then again, it's for charity, not corporate profit. Many shows make a one-off special for the event. It's very much like Children In Need (coming up in November) but nominally funnier. IMO Children In Need is often funnier because it's only s'posed to be lighthearted so there's no pressure on performers. Oh, did you say John Barrowman is in it this year? Oh, really? Not that that makes me more inclined towards it or anything...
Sainsbury's are a big sponsor of Comic Relief (all the big four have their own charities) so this is a way to slowly sneak it into your consciousness... Asda make a big deal of
Children In Need for example.
ETA - found
this on Wiki. Says what I did (phew!) but in more detail in case you're completely fascinated. Inserted a link for CIN to be fair.
ETA - again. Comic Relief happened this year. I missed it. I think. I can only assume my parents were away and I was drunk. Or they were home and I was drunk. I was drunk a lot early this year. So the sauces are probably reduced because they are nearing expiration date, as opposed to being released early. Not being afraid of things like expiration dates I will buy them up and use them until the end of the next century (or until I run out, or die) and recommend everyone else to do so.