From the BBC:
In the case of time-space synaesthesia, a very visual experience can be triggered by thinking about time.
"I thought everyone thought like I did, says Holly Branigan, also a scientist at Edinburgh University, and someone with time-space synaesthesia.
"I found out when I attended a talk in the department that Julia was giving. She said that some synaesthetes can see time. And I thought, 'Oh my god, that means I've got synaesthesia'."
So what exactly does she see?
"For me it's a bit like a running track," she says.
"The track is organised around the academic year. The short ends are the summer and Christmas holidays - the summer holiday is slightly longer.
"It's as if I'm in the centre and I'm turning around slowly as the year goes by. If I think ahead to the future, my perspective will shift."