Time

primitive: current-time

Returns the number of seconds since 1970-01-01 00:00:00 UTC, excluding leap seconds.

primitive: gettimeofday

Returns a pair containing the number of seconds and microseconds since 1970-01-01 00:00:00 UTC, excluding leap seconds. Note: whether true microsecond resolution is available depends on the operating system.

The following procedures either accept an object representing a broken down time and return a selected component, or accept an object representing a broken down time and a value and set the component to the value. The numbers in parentheses give the usual range.

tm:sec, set-tm:sec

Seconds (0-59).

tm:min, set-tm:min

Minutes (0-59).

tm:hour, set-tm:hour

Hours (0-23).

tm:mday, set-tm:mday

Day of the month (1-31).

tm:mon, set-tm:mon

Month (0-11).

tm:year, set-tm:year

Year (70-), the year minus 1900.

tm:wday, set-tm:wday

Day of the week (0-6) with Sunday represented as 0.

tm:yday, set-tm:yday

Day of the year (0-364, 365 in leap years).

tm:isdst, set-tm:isdst

Daylight saving indicator (0 for "no", greater than 0 for "yes", less than 0 for "unknown").

tm:gmtoff, set-tm:gmtoff

Time zone offset in seconds west of UTC (-46800 to 43200).

tm:zone, set-tm:zone

Time zone label (a string), not necessarily unique.

primitive: localtime time [zone]

Returns an object representing the broken down components of time, an integer like the one returned by current-time. The time zone for the calculation is optionally specified by zone (a string), otherwise the TZ environment variable or the system default is used.

primitive: gmtime time

Returns an object representing the broken down components of time, an integer like the one returned by current-time. The values are calculated for UTC.

primitive: mktime bd-time [zone]

bd-time is an object representing broken down time and zone is an optional time zone specifier (otherwise the TZ environment variable or the system default is used).

Returns a pair: the CAR is a corresponding integer time value like that returned by current-time; the CDR is a broken down time object, similar to as bd-time but with normalized values.

primitive: tzset

Initialize the timezone from the TZ environment variable or the system default. Usually this is done automatically by other procedures which use the time zone, but this procedure may need to be used if TZ is changed.

primitive: strftime template time

Formats a time specification time using template. time is an object with time components in the form returned by localtime or gmtime. template is a string which can include formatting specifications introduced by a % character. The formatting of month and day names is dependent on the current locale. The value returned is the formatted string. See section `Formatting Date and Time' in The GNU C Library Reference Manual.)

primitive: strptime template string

Performs the reverse action to strftime, parsing string according to the specification supplied in template. The interpretation of month and day names is dependent on the current locale. The value returned is a pair. The CAR has an object with time components in the form returned by localtime or gmtime, but the time zone components are not usefully set. The CDR reports the number of characters from string which were used for the conversion.

Variable: internal-time-units-per-second

The value of this variable is the number of time units per second reported by the following procedures.

primitive: times

Returns an object with information about real and processor time. The following procedures accept such an object as an argument and return a selected component:

tms:clock

The current real time, expressed as time units relative to an arbitrary base.

tms:utime

The CPU time units used by the calling process.

tms:stime

The CPU time units used by the system on behalf of the calling process.

tms:cutime

The CPU time units used by terminated child processes of the calling process, whose status has been collected (e.g., using waitpid).

tms:cstime

Similarly, the CPU times units used by the system on behalf of terminated child processes.

primitive: get-internal-real-time

Returns the number of time units since the interpreter was started.

primitive: get-internal-run-time

Returns the number of time units of processor time used by the interpreter. Both "system" and "user" time are included but subprocesses are not.

Go to the first, previous, next, last section, table of contents.