Time

Introduction

Timing is crucial to OpenBOR, as it is to most game engines. Understanding how the engine measures time, and how those measurements affect a project, is therefore essential.

OpenBOR uses a modern decoupled timing model by default. This means gameplay simulation and display rendering operate as independent loops, with the simulation advancing at regular 5-millisecond intervals.

The gameplay loop advances movement, animation, collision, combat, entity behavior, and other world systems according to the logical clock. The rendering loop draws the latest available world state according to the selected display rate. Since neither loop depends on the other to advance, changes in display performance, refresh rate, or VSync behavior do not ordinarily change the speed or timing of gameplay.

Logical Time vs. FPS

Logical time controls how frequently OpenBOR updates the simulated game world. Frames per second, or FPS, control how frequently the display loop renders that world. These are separate rates serving different purposes.

OpenBOR’s logical clock runs at 200 ticks per second by default. Each logical tick therefore represents 5 milliseconds. The display loop, running at 60 FPS, renders once every 16.67 milliseconds. Since the two loops are decoupled, they do not need to align one-to-one. Under these default rates, OpenBOR ordinarily processes three or four logical ticks between displayed frames.

Gameplay durations remain based on logical time regardless of how often the world is drawn. Running the display loop at 60, 200, 500, VSync, or an unrestricted rate does not reinterpret an animation delay, effect duration, movement timer, or other logical-time value.

OpenBOR also provides an optional frame-aligned timing mode for projects that use traditional frame-count conventions. Creators may configure the logical clock to a rate evenly divisible by the desired frame rate and express animation delays as direct logical ticks. For example, a 180 Hz logical clock provides exactly three logical ticks for every interval of a 60 Hz timeline:

delay 3 direct

This represents one 60 Hz frame interval. Values of 6 direct, 9 direct, and 12 direct represent two, three, and four frame intervals respectively. Frame-based timing can therefore be expressed exactly without coupling gameplay simulation to display rendering.

See Logical clock precision for more information about animation timing and direct delays.

OpenBOR exposes the following primary measurements of time:

Game Time

Game Time is the traditional beat ’em up countdown used to maintain the pace of a level. It is a gameplay rule rather than the engine’s logical clock.

When Game Time expires, players ordinarily lose a life. Creators may disable, remove, replace, or otherwise modify this behavior.

See Game Time.

Elapsed Time

Elapsed Time is the current level’s logical clock. It begins at `0` when active level gameplay starts and increments once for every processed logical tick.

At the default 200 Hz logical rate, each increment represents 5 milliseconds. Animation timing, effect durations, entity simulation, and most other gameplay processes use Elapsed Time or values derived from it.

See Elapsed Time.

Ticks

Ticks measure the number of milliseconds elapsed since OpenBOR started. Unlike Elapsed Time, Ticks are not limited to an active level and do not reset when a level begins.

Ticks are useful for loading operations, menus, recorded input, diagnostics, and script timers that must remain available outside active gameplay.

See Ticks.

System Time

System Time provides optional access to the host device’s real-world clock, including Unix timestamps, calendar dates, local time, and Coordinated Universal Time.

Native gameplay does not depend on System Time. Creators may use it through script for features such as dated save files, logging, calendar events, or other intentionally real-world behavior.

See System Time.

Game Time

Game time is a default countdown timer that appears at top center of the screen during an active level. It starts at 99 and decrements once every two real world seconds. At 0, all active players take damage equal to their current HP, and the game is over if no lives or credits remain. Time resets automatically when players clear a designated level wait and at the start of each new level.

The Batman Savage Dawn fan game demonstrates OpenBOR's default game timer in action at top center of the screen.

Set Time

settime {int time}

#default
settime 99

Level header command that sets value applied to timer on level start and native resets.

• Accepts any integer value from 0 to 99. Out of bounds values are ignored.
• 0 = infinite time.

HUD Display

For configuring how timer displays on screen, see Heads Up Display.

• Disable Time Display
• Timer Font
• Timer Location
• Timer Icon

Other

data/sounds/timeover.wav

If available, plays once when the game timer expires.

anim lose

If available, entity plays this animation in place of normal death when game timer expires.

• Accessible to script as openborconstant("ANI_LOSE").

anim falllose

If available and entity does not have a lose animation, entity plays this animation in place of normal fall death when game timer expires.

• Accessible to script as openborconstant("ANI_FALLLOSE").

Attack types

Attack types applied to players when game time expires.

• openborconstant("ATK_TIMEOVER") - Applied to players without a lose animation.
• openborconstant("ATK_LOSE") - Applied to players with a lose animation.

Script API

Game Time

Current game time is read and write accessible.

Get

int time = openborvariant("game_time");

Get integer representing game time remaining.

Set

int new_time = 50;

setopenborvariat("game_time", new_time);

Set game time remaining.

Timetick Event

If available, data/scripts/timetick.c fires on each game time decrement. Populates the following local variables.

• time - Current game time value.

Elapsed Time

In terms of game mechanics, Elapsed Time is OpenBOR’s most important and frequently used time measurement because it represents the engine’s logical clock. Its implementation, however, is relatively simple.

At the beginning of each level, a global elapsed-time counter is initialized to 0. OpenBOR’s logical clock runs at 200 ticks per second (200 Hz) by default, and the counter increments by 1 for every processed logical tick.

At 200 Hz, each logical tick represents 5 milliseconds, or one-half of a centisecond. Therefore:

• 2 elapsed-time ticks equal 1 centisecond.
• 200 elapsed-time ticks equal 1 second.

OpenBOR’s logical clock operates independently of its outer update and rendering rate. Depending on the selected FPS setting and display synchronization, the outer update cycle may execute faster or slower than the logical clock. Available FPS settings include VSync, fixed limits of 60, 200, or 500 FPS, and an unrestricted option.

Some operations execute once per outer update cycle. These include the global update.c and updated.c script events. Such scripts may therefore execute at a different frequency than the logical clock.

Other operations, including entity simulation and entity update scripts, execute according to logical ticks.

Elapsed Time is therefore reliable as a gameplay timer regardless of the selected outer frame rate. Manually incremented script timers may produce inconsistent results when incremented from an event that executes once per outer update cycle. For timing operations outside active gameplay, where Elapsed Time is unavailable, consider using Ticks instead.

Duration Testing

Most timed systems operate by setting an expiration value equal to the current Elapsed Time plus a predetermined duration. The engine then compares that expiration value against the elapsed-time counter. Once Elapsed Time reaches or passes the expiration value, the timed item may complete, expire, continue to another state, or perform whatever other action its system requires.

/* Set expiration. */
int expiration = elapsed_time + duration;

/*
* "Reach or exceed" logic downstream.
*/
if(elapsed_time >= expiration) {
    // Take action.
}

Note: In case it matters, the Elapsed Time counter is stored as a 64-bit unsigned integer. At 200 increments per second, a single level could run continuously for roughly 2.9 billion years before the counter rolls over.

Script API

Get Elapsed Time

int elapsed_time = openborvariant("elapsed_time");

Set Elapsed Time

Be careful about setting elapsed time during game-play, as again, virtually every active game timing property depends on it.

int new_time = 100

setopenborvariant("elapsed_time", new_time);

Ticks

Ticks is a read only measure of milliseconds starting from game boot. OpenBOR natively uses ticks for the player input recording feature and for timing during load screens. Ticks therefore do not generally affect active game-play, but are useful for user content, scripting, and keeping time outside of active game-play elements when Elapsed Time is not natively incremented.

Script API

Get Ticks

int ticks = openborvariant("ticks");

System Time

System time is entirely optional and provided for creator defined script use. It is not accessed by native engine logic in any way. System time is available as a Unix timestamp in either seconds or milliseconds where supported by hardware. Conversion functions allow outputting a custom formatted string or time parts as integer values for use in logic expressions.

Script API

Get Current Unix Timestamp

Returns the current system time as the number of seconds elapsed since 1970-01-01 00:00:00 UTC.

int timestamp = datetime_gettimestamp();

Get Current Unix Timestamp in Milliseconds

Returns the current system time as the number of milliseconds elapsed since 1970-01-01 00:00:00 UTC.

Note: Millisecond Unix timestamps require a 64-bit integer value.

int timestamp = datetime_gettimestampms();

Format Current Local Date and Time

Formats the current system time as a string using the host system's local time standard. The format string uses standard datetime conversion codes.

Note: Names such as weekdays and months may vary according to the host system's configured language and locale.

void date_time = datetime_format("%Y-%m-%d %H:%M:%S");

The following examples demonstrate several common formats:

/*
* ISO-style date and 24-hour time:
* 2026-07-12 14:35:08
*/
void date_time = datetime_format("%Y-%m-%d %H:%M:%S");

/*
* Month, day, and year:
* 07/12/2026
*/
void date = datetime_format("%m/%d/%Y");

/*
* Full weekday and month names:
* Sunday, July 12, 2026
*/
void written_date = datetime_format("%A, %B %d, %Y");

/*
* Abbreviated weekday and month names:
* Sun, Jul 12, 2026
*/
void short_date = datetime_format("%a, %b %d, %Y");

/*
* 12-hour time with AM or PM:
* 02:35:08 PM
*/
void time_12_hour = datetime_format("%I:%M:%S %p");

/*
* 24-hour time:
* 14:35:08
*/
void time_24_hour = datetime_format("%H:%M:%S");

/*
* Year, month, day, hour, and minute:
* 20260712_1435
*
* Useful for save names, logs, and generated filenames.
*/
void file_timestamp = datetime_format("%Y%m%d_%H%M");

/*
* Day of the year:
* Day 193 of 2026
*/
void year_progress = datetime_format("Day %j of %Y");

/*
* Weekday name:
* Sunday
*/
void weekday = datetime_format("%A");

Format a Unix Timestamp

Formats a supplied Unix timestamp expressed in milliseconds.

int timestamp = 1783890000000;

void date_time = datetime_format("%Y-%m-%d %H:%M:%S", timestamp);

Format Date and Time as UTC

All format and date part functions can accept the following constants:

• opeborcosntat("DATETIME_STANDARD_LOCAL") - Use local system time (default).
• opeborcosntat("DATETIME_STANDARD_UTC") - Use Coordinated Universal Time.

Formats a supplied Unix timestamp using Coordinated Universal Time instead of the host system's local time.

int timestamp = datetime_gettimestampms();

void date_time = datetime_format("%Y-%m-%d %H:%M:%S", timestamp, opeborcosntat("DATETIME_STANDARD_UTC"));

Get Current Year

Returns the current four-digit year using the host system's local time standard.

int year = datetime_getyear();

Get Current Month

Returns the current calendar month as an integer.

int month = datetime_getmonth();

Get Current Day

Returns the current day of the month as an integer.

int day = datetime_getday();

Get Current Weekday

Return the current day of the week as an integer corresponding to one of the following constants:

openborconstant("DATETIME_WEEKDAY_SUNDAY")
openborconstant("DATETIME_WEEKDAY_MONDAY")
openborconstant("DATETIME_WEEKDAY_TUESDAY")
openborconstant("DATETIME_WEEKDAY_WEDNESDAY")
openborconstant("DATETIME_WEEKDAY_THURSDAY")
openborconstant("DATETIME_WEEKDAY_FRIDAY")
openborconstant("DATETIME_WEEKDAY_SATURDAY")

int weekday = datetime_getweekday();

/* Is it Monday? */
if(weekday == openborconstant("DATETIME_WEEKDAY_MONDAY")){
    log("Just another Manic Monday.");
}

Get Current Hour

Returns the current hour using the host system's local time standard.

int hour = datetime_gethour();

Get Current Minute

Returns the current minute of the hour.

int minute = datetime_getminute();

Get Current Second

Returns the current second of the minute.

int second = datetime_getsecond();

Get Date and Time Parts from a Unix Timestamp

Each component function optionally accepts a Unix timestamp expressed in milliseconds. This allows creators to extract individual date and time values from a stored timestamp.

int timestamp = 1783890000000;

int year   = datetime_getyear(timestamp);
int month  = datetime_getmonth(timestamp);
int day    = datetime_getday(timestamp);
int hour   = datetime_gethour(timestamp);
int minute = datetime_getminute(timestamp);
int second = datetime_getsecond(timestamp);

Get Date and Time Parts as UTC

Pass opeborcosntat("DATETIME_STANDARD_UTC") as the second argument to interpret the supplied timestamp as Coordinated Universal Time.

int timestamp = datetime_gettimestampms();

int year = datetime_getyear(timestamp, opeborcosntat("DATETIME_STANDARD_UTC"));

int month = datetime_getmonth(timestamp, opeborcosntat("DATETIME_STANDARD_UTC"));

int day = datetime_getday(timestamp, opeborcosntat("DATETIME_STANDARD_UTC"));

int hour = datetime_gethour(timestamp, opeborcosntat("DATETIME_STANDARD_UTC"));

Use Current Time with an Explicit Time Standard

Pass `NULL()` for the optional timestamp argument when selecting a time standard without supplying a custom timestamp.

int utc_hour = datetime_gethour(NULL(), opeborcosntat("DATETIME_STANDARD_UTC"));