By Jonathan Head
BBC News, Yogyakarta
If you believe in the significance of anniversaries, there could still be plenty to fear from Mount Merapi, the volcano on Java which has been spewing out ash and lava for the past three weeks.
Local people say they know what to expect from the volcano
Travel a short distance west of the mountain, and you come across the magnificent Buddhist monument of Borobudur.
It was built during the eighth and ninth centuries, but its breathtaking reliefs and stupas were hidden from the rest of the world for eight centuries, after a massive eruption by Merapi covered it with ash.
The year was 1006, the last time the volcano really blew its top.
Since then Merapi has been very active, but confined itself to smaller eruptions that only endanger those living on its upper slopes.
And despite the anniversary, that is all the vulcanologists believe it is going to do this time.
The millions of people crowded lower down, under Merapi's shadow, are not at risk from a Krakatoa-style cataclysm. But the mountain is still unpredictable; its cone is steep and fragile.
So the government is trying to persuade the several thousand who live in higher villages that they must stay in the temporary camps, set up in schools and public buildings.
It is not having much success. Although all the roads leading up into the danger zone are now barred by police road-blocks, they invariably allow local residents to go back to their villages to look after their homes and livestock.
When we drove nervously up to the highest village on Merapi's southern slope, all the men were sitting there, apparently unconcerned by all the volcanic activity 1,000 metres above them.
We know this mountain, they said. We don't believe it's going to do anything dramatic.
Most of the women, children and elderly are still hanging on in the camps, but their patience is wearing thin.
There is a pretty well-oiled relief operation looking after them, but still they are starting to complain about the food, the cramped sleeping quarters, and an assortment of ailments afflicting the children. They want to go home.
People are tired of camp life and want to go home
You would think the experience of a neighbouring village 12 years ago would counsel more caution. Then there were eruptions on a similar scale to those of the past three weeks, and they were also ignored by local people.
Sixty died horrible deaths after being engulfed in a scalding cloud of gas that spewed suddenly out of the crater.
But the local people do not listen to government officials. They listen to Marijan, the old "gate-keeper" to the volcano who enjoys an intimate spiritual relationship with Merapi.
He insists there is nothing to worry about, and he has refused official pleading that he set an example to everyone else and come down from the danger zone.
Merapi is much more than just a mountain to the people of central Java.
Mt Merapi is sacred to the people of central Java
It is seen as a representation of the sacred Mount Meru of Hindu mythology, or as the home of more ancient Javanese spirits, and as one of the forces governing the fortunes of the old royal city of Yogyakarta, along with Ratu Kidul, the treacherous goddess of the south seas.
The Sultan of Yogyakarta, although a devout Muslim like most of his subjects, pays homage to these forces in yearly rituals.
Benign or malevolent, they are something people here have lived with for so long it is difficult for them to take the warnings of the vulcanologists that seriously.
If Merapi does live up to its reputation for dangerous unpredictability, there is still a chance that someone will get hurt.