# Environment (functions)

- [BIS_fnc_calculateDateTime](../../functions/BIS_fnc_calculateDateTime.md): Returns the end datetime if an offset is passed, or the offset between start and end dates.
- [BIS_fnc_compareDateTimes](../../functions/BIS_fnc_compareDateTimes.md): Returns the newer date or returns true if they are identical.
- [BIS_fnc_createRuin](../../functions/BIS_fnc_createRuin.md): Create a building ruin and hide the original object.
- [BIS_fnc_crows](../../functions/BIS_fnc_crows.md): Spawns flock of crows circling the area.
- [BIS_fnc_destroyCity](../../functions/BIS_fnc_destroyCity.md): Destroys building in given area based on input seed.
- [BIS_fnc_earthquake](../../functions/BIS_fnc_earthquake.md): Earthquake simulated through camera shake and sound. Stamina is impacted by the earthquake too. Earthquake will last between 13 and 20 seconds.
- [BIS_fnc_fixDate](../../functions/BIS_fnc_fixDate.md): Checks the array with date data and makes sure the values are within the boundries.
- [BIS_fnc_flies](../../functions/BIS_fnc_flies.md): Spawns flies around position.
- [BIS_fnc_interpolateWeather](../../functions/BIS_fnc_interpolateWeather.md): Interpolate weather (overcast and fog) according to 2 boundry dates and their weather conditions.
- [BIS_fnc_isDateTimeNewer](../../functions/BIS_fnc_isDateTimeNewer.md): Returns true if the first passed datetime is newer than the second one.
- [BIS_fnc_isLeapYear](../../functions/BIS_fnc_isLeapYear.md): Returns true if given year is a leap year, otherwise false.
- [BIS_fnc_monthDays](../../functions/BIS_fnc_monthDays.md): Returns number of days in given month. Takes in account for leap year.
- [BIS_fnc_sandstorm](../../functions/BIS_fnc_sandstorm.md): Creates particle sandstorm round given object.
- [BIS_fnc_setDate](../../functions/BIS_fnc_setDate.md): Instantly set date and share it across network with optional transition effect.
- [BIS_fnc_setFog](../../functions/BIS_fnc_setFog.md): Instantly set weather conditions and share it across network.
- [BIS_fnc_setOvercast](../../functions/BIS_fnc_setOvercast.md): Instantly set weather conditions and share it across network. Must be executed in scheduled environment.
- [BIS_fnc_setRain](../../functions/BIS_fnc_setRain.md): A helper function for setting rainParams in multiplayer. The call to the function could be placed in init.sqf to sync rainParams between all clients and JIP. Alternatively execute on server.
- [BIS_fnc_showTime](../../functions/BIS_fnc_showTime.md): Shows time gap between two dates.
- [BIS_fnc_sunriseSunsetTime](../../functions/BIS_fnc_sunriseSunsetTime.md): Calculate sunrise and sunset time.