'Sham el Nessim' is a festival and holiday celebrated by all people in Egypt, and seemingly goes back to the time of the pharaohs (4500 years ago!). It is basically their celebration of the coming of spring (the scent of the breeze) and is celebrated on the Monday directly after the Coptic Easter day.(i.e. this year it was 9th April- so only a month late writing up about it!!!!) People have the day off work and usually go for a picnic- and eat Fiseekh (a raw salted fish) it is very smelly!!! Unfortunately often it smells funny because it is bad and many people end up in hospital round sham el Nessim from fish food poisoning! People often boil and colour eggs (coloured eggs also date back to pharonics times and are the direct root of our 'Easter eggs'. They were believed to symbolize regeneration of life. Spring onions were once used to cure the son of a pharaoh and so nowadays are also on the spring menu!
This is a festival for all- and is one of the few big public holidays which are non-Islamic.
Around the time of this celebration there are always sandstorms (khamaseen). We had a pretty major one (photo below taken from my living room window!) but I heard that it actually did kill people- not to mention causing severe road accidents out of town where you couldn't even see the road- far worse than fog!!!