The Celtic festival of Samhain, (pronounced Sow-wen), is held in Autumn. 
It's the beginning of the New Year in the Cycle of Life, according to the Celts. 
In Europe and America, it's celebrated at the end of October. 
Here, we celebrate it at the end of April. 
The Celtic festivals were driven by the seasons, not the calendar, 
so our cycle in Australia is opposite to that overseas. 

The modern version of Samhain is Halloween. 
Most of the mythology surrounding that, though, is Christian-based, with witches in pointy hats, ghosts and ghouls wandering the night, etc. 
Though the jack-o-lantern, a candle inside a carved pumpkin face (which was actually a turnip, or something like that) was used by the common folk to place outside their doors  in the hope of warding off bad spirits who might be at large that night. 

For us, it is the Feast of the Dead, and there are some cultures, like in Mexico and Japan,
who still celebrate such things.  It is an honouring of our ancestors, and of friends and relatives and situations that have passed from our lives in the previous year. 
We place photos and mementos of them on a table, and light candles to burn all night in their honour.  And we write symbolic letters of love, and regret, and forgiveness - 
of all the things we wanted to say and left unsaid, or wanted to repeat, just so our loved ones might know of it - and we burn them in a brazier so that the smoke might transport them into the ether, and our loved ones might get a whiff of our messages... 

It's a very healing and peaceful thing to do, and helps many of us to achieve a sense of closure for hose relationships which we have not been able to let go.  And we place an extra plate and cup at our feast table for the honoured guests of the Otherworld, 
welcoming them to our feast to join in our revelry as they might have done when they were part of our lives. 

I love Samhain, and never fail to feel the presence of my grandmother at it. 
I feel surrounded by love and warmth. 
 

We tend to think of spirit as being cold and windy, but the spirits of those who love us are
so pleasant and warm.  It's just lovely having them visit. 

Samhain is not a fearful time.  There are no evil spirits wandering the earth to trap the unwary.  Only the invited are able to cross the barriers between worlds and join the revelries.  It's just a party, and a social gathering, with a difference.  And why shouldn't we invite the loved ones who are in spirit?  If we really believe what we profess, that spirit is simply another stage of our lives, then there's nothing ghoulish about it at all. 

An afterthought - you know, it's pretty apt that ANZAC day is celebrated on April 25 in Australia, isn't it?  A day to honour our dead...at the end of April...