Anniversaries figure prominently in Northern Ireland politics. Often the pace and the timing of progress are hostage to calendar dates. Some believe we don't move forward because we can't avoid looking back.
January 2020 marks one year since dissident republicans exploded a bomb outside the courthouse in Derry. It also marks 48 years since 13 Derry men were shot dead on Bloody Sunday.
At first glance, the two events don't seem to be linked, but one is having an adverse effect on the other. For decades, the Bloody Sunday families campaigned for the Parachute Regiment soldiers who opened fire to be charged.
One paratrooper - known only as Soldier F - is accused of two murders. There was a hope - maybe even an expectation - that he would be charged in a courtroom in Derry, even if any subsequent trial would take place elsewhere.
But the courthouse bomb attack, allied to the ongoing threat posed by dissidents, means the case must move to the Laganside court centre in Belfast. A judge has ruled that security concerns make Derry too dangerous.
So the anniversary of Bloody Sunday is approaching, but the Bloody Sunday families may never see a paratrooper brought before a court in the city to answer for what happened on 30 January 1972.
And when that anniversary passes, our thoughts will turn to other looming dates. We will reflect on the murder of young journalist Lyra McKee. In the run up to Easter 2019, she was shot dead by dissident republicans whilst reporting on a riot in Derry's Creggan area.
The public outcry against her murder was astonishing, and in response, the dissidents cancelled their annual Easter Monday parade.
But Easter 2020 now approaches, and there are plans for the dissident parade to be resurrected, perhaps passing the very spot where Lyra's young life was cruelly cut short.
The pages of the calendar will once again be torn away to reveal more heartache, more pain, more anger. We cannot avoid looking back.