DayZ Day Length, Night Speed and Weather
Control how long DayZ days and nights last with time acceleration, keep nights short, choose a start time, and edit the weather in cfgweather.xml.
The Two Speed Settings
DayZ's clock is controlled by two multipliers in serverDZ.cfg, both set on the Settings tab:
serverTimeAcceleration(0.1 to 64): how fast time runs. 1 is real time. 12 makes a full 24-hour in-game day pass in 2 real hours, 24 in 1 hour.serverNightTimeAcceleration(0.1 to 64): an extra multiplier that applies only at night, on top of the first one. With time acceleration 12 and night acceleration 4, nights run 48 times faster than real time.
The second setting is the one most server owners want: it keeps nights short without rushing the day.
Worked Examples
Real-world lengths, assuming roughly half of the in-game day is dark. The exact split depends on the in-game date, so treat these as approximate.
| Time acceleration | Night acceleration | Daylight lasts | Night lasts | Style |
|---|---|---|---|---|
| 1 | 1 | about 12 hours | about 12 hours | Real time |
| 4 | 1 | about 3 hours | about 3 hours | Slow, immersive |
| 6 | 6 | about 2 hours | about 20 minutes | Long days, short nights |
| 12 | 1 | about 60 minutes | about 60 minutes | Common community default |
| 12 | 4 | about 60 minutes | about 15 minutes | Popular "short nights" setup |
| 24 | 8 | about 30 minutes | under 4 minutes | Nights barely happen |
Tip: pick the day length you want first, then raise night acceleration until nights feel right. Leaving some darkness keeps flashlights, flares and night-vision loot worth having.
Start Time and Persistent Time
serverTime = "SystemTime";starts at the host clock's time of day.serverTime = "2024/9/25/08/00";(formatYYYY/MM/DD/HH/MM) starts at a fixed time, here 8 am. Bohemia's vanilla mission keeps the date within late September to late October on every start, so in practice it is the hour and minute that matter.serverTimePersistent = 1;saves the in-game clock and continues from it after a restart, instead of going back to the start time.
Always day: set a morning start time, turn persistent time off, and restart the server more often than one in-game day lasts. With time acceleration 1, a restart every 6 hours from 8 am never reaches dusk.
Always the same time after a restart: turn persistent time off. With it on, the start time is ignored once a time has been saved.
Darker Nights
How dark night looks is a separate setting from how long it lasts:
lightingConfig0 gives brighter nights, 1 dark nights, 2 the lighting designed for Sakhal.disablePersonalLight1 removes the faint glow around each player.
Dark nights with no personal light is the hardcore combination. If enableCfgGameplayFile is 1, both are controlled from cfggameplay.json instead (WorldsData.lightingConfig and PlayerData.disablePersonalLight). See cfggameplay.json, Spawn Points and Starting Gear.
Weather: cfgweather.xml
Weather is set per map in mpmissions/<mission>/cfgweather.xml: the ranges and change rates for overcast, fog, rain, wind and snow.
The vanilla file ships switched off (
enable="0"on its root element), so the game uses its built-in weather and your edits do nothing. Change it toenable="1"before editing values.
Common changes:
- Less fog: lower the maximum fog value.
- Less rain: lower the maximum rain value or raise the overcast threshold rain needs.
- No storms: lower the maximum overcast and wind.
Weather is not saved between restarts; it starts again from the file's rules each time.
Take a backup before editing, keep the XML valid, and restart to apply. A broken file makes the server ignore it or stop at start-up; the .RPT log in profiles/ names the problem.
Applying Changes
Every time and weather change needs a Restart from the status bar. DayZ reads serverDZ.cfg and the mission files only when it starts.
Players already in game see the new time as soon as they reconnect after the restart.