40d:Time

Time in Dwarf Fortress is can be a somewhat complicated subject, but learning the ins and outs of the system is essential for modders and can be of great use to players, as time tracks everything from syndromes to crop growth.

Breakdown

Time is measured in unnamed units, which are often colloquially referred to as "Time Units." A time unit is roughly equivalent to 1.2 minutes.

The average dwarf (presumably one with 1000 speed, though this needs verification) takes 10 time units to make any sort of move, delayed mechanical actions (like raising a bridge or floodgate) take 100 time units.

There are 1200 time units in a day, 28 days in a month, and 336 days in a year.

A year contains 403200 time units.

Syndromes

Syndromes use time units. A syndrome that lists its effect as starting at "5" means that for all but the fastest characters, you will begin feeling the effects as soon as you take a step. "50" means 50 time units (or about five steps), and "500" reliably suggests that you'll be able to stagger all the way back to the hospital before your brain pours out of your ears.

Plants

Plants use a tag called Growdur. The Grodur value is generally set to 300 or 500, which is actually 30000 or 50000. 1 growdur = 100 time units.

Fortress Mode

Time passes more quickly in Fortress Mode, specifically, seven times more quickly. It takes an average dwarf 70 time units (or 8.4 minutes!) to take a single step in Fortress Mode. Be advised that syndromes will set in much more quickly, and it is important to have hospital services on hand and ready to spring into action at a moment's notice.

Or, you know, not. They're just dwarves, after all, and there's always another wave of migrants ready to take their place. Armok giveth, and Armok taketh away.