Day length and time in Project Zomboid

Day Length sets how many real minutes one in-game day of 24 hours lasts. You find it under Time when you build a custom sandbox, and it can also be changed in the presets before a game starts. The default in every standard mode is one real hour per in-game day. Challenges use fixed rules and cannot be changed. The full list of other sandbox options is on the sandbox settings page.

The shortest choices are 15 and 30 minutes. Above one hour the list steps up an hour at a time, and the longest choice is a real-time day, where 24 game hours take 24 real hours. Guides agree on the short end and the real-time top, but none we read listed every step in between for Build 42, so check the dropdown in your build.

The math is simple: divide the day length in real minutes by 24 to get real minutes per game hour.

The key idea is that the world runs on the game clock, while your own actions run on real time. Anything measured in game hours or game days takes longer in real minutes when you raise Day Length. Things that take a fixed number of seconds to perform, such as swinging a weapon, walking a street or most timed actions, take about the same real time, so they use up fewer game minutes.

Sources agree that hunger, thirst, fatigue, crop growth and spoilage follow the game clock. Healing, fuel and cooking are less clearly documented, but they are tracked in game time in the item and health systems, so we expect them to follow the same rule. One Steam reply claims reading and sleeping take longer on longer days, while another player found reading and cooking unchanged; we list this under checks. The oven timer counts game minutes, so if cooking follows it, a meal on a 2-hour day takes twice the real time of the same meal on the default. See cooking, crops, food preservation and health for each system.

Skill XP does not change with Day Length. What changes is how much you can do between sunrise and sunset, so a longer day means more grinding per game day and faster progress against the calendar. That is a big part of why longer days feel easier: you reach useful skill levels before power and water go off. The skill leveling guide has the XP numbers.

In single player you can change the game speed at any time with the buttons next to the clock or with the keyboard. The community key list gives F2 for pause, F3 for normal speed and F4 to F6 for three faster speeds, described there as 3, 10 and 20 times normal (one source). Rebind them in the Keyboard tab if needed; the controls page lists defaults.

Fast forward skips the waiting, not the danger. Zombies still move and needs still drop, so only speed up when you are safe indoors, for example while a long craft finishes or crops grow. In single player the game usually drops back to normal speed when a zombie comes into view. Fast forward and pause are not available in multiplayer, where time runs at the server's Day Length for everyone; see multiplayer.

Sleeping is the other way to skip hours. In single player the clock runs very fast while your character sleeps, so a full night takes a few real seconds whatever the Day Length. You can set an alarm, and waking early from a noise or a zombie is possible. The sleep page covers beds, fatigue and the sleeping pill and insomnia details.

In multiplayer, sleep does not speed up the shared clock. Servers can choose whether players can sleep at all and whether sleep is needed, so on many servers fatigue is turned off and night has to be lived through in real time. Long day lengths on a server mean long real nights, which is a reason some groups pick 2 to 4 hours rather than more. See hosting a server for the server-side options.

Opinion these are starting points, not rules. Pair them with the presets on the recommended settings page.

Very long days remove much of the time pressure. Looting a town before the power goes off becomes easy, and some players feel real time breaks the balance. If you want the slower feel without making the game trivial, raise Day Length and shorten the water and electricity shutoff settings to match. Longer days also mean longer nights in real time, and nights are when the game is most dangerous; see seasons for how daylight changes through the year.