I work on software tool for making character's backgrounds/storylines. There may be a couple hundreds of PCs and NPCs with background events. One of the important part of the system is event concept. I use standard Gregorian calendar for events but in imaginary worlds it is not always well suitable.
I tried to find existing solution for custom calendar but without success. How it should look like in my vision:
possibility to specify different time measurement cycles
visualize such calendar
ideally it should generate timeline
Does anybody know something like this?