Constants: Date and Time

Use the DATE keyword (D) to specify a date.

Syntax

<date keyword>#<year>-<month>-<day>

<date keyword> : DATE | date | D | d
<year> : 1970-2106
<month> : 1-12
<day> : 1-31

DATE literals are treated internally as data type DWORD, which corresponds to an upper limit of DATE#2106-2-7.

PROGRAM PRG_Date
VAR
        dateStart : DATE := DATE#2018-8-8;
        dateEnd : DATE := D#2018-8-31;
        dateCompare: DATE := date#1996-05-06;
        xIsDuringTheTime: BOOL;

        dateEarliest : DATE := d#1970-1-1; // = 0
        dateLatest : DATE := DATE#2106-2-7; // = 4294967295
END_VAR

IF dateStart < dateCompare THEN
        IF dateCompare < dateEnd THEN
                xIsDuringTheTime := TRUE;
        END_IF;
END_IF

Use the LDATE keyword (LD) to specify a date.

Syntax

<date keyword>#<year>-<month>-<day>

<date keyword> : LDATE | ldate | LD | ld
<year> : 1677-2262
<month> : 1-12
<day> : 1-31

LDATE literals are treated internally as data type LWORD, which corresponds to an upper limit of DATE#2554-7-21.

PROGRAM PRG_Ldate
VAR
        ldateStart : LDATE := LDATE#2018-8-8;
        ldateEnd : LDATE := ldate#2018-8-31;
        ldateCompare: LDATE := LD#1996-05-06;
        xIsDuringTheTime: BOOL;

        ldateEarliest : LDATE := ld#1677-9-22; // = 0
        ldateLatest : LDATE := LDATE#2262-4-11; // = 16#7FFFB21D1DB10000

        lwValue: LWORD;
END_VAR

IF ldateStart < ldateCompare THEN
        IF ldateCompare < ldateEnd THEN
                xIsDuringTheTime := TRUE;
        END_IF;
END_IF
lwValue := LDATE_TO_LWORD(ldateCompare);

Use the DATE_AND_TIME keyword (DT) to specify a date and time.

Syntax

<date and time keyword>#<date and time value>

<date and time keyword> : DATE_AND_TIME | date_and_time | DT | dt
<date and time value> : <year>-<month>-<day>-<hour>:<minute>:<second>
<year> : 1970-2106
<month> : 1-12
<day> : 1-31
<hour> : 0-24
<minute> : 0-59
<second> : 0-59

DATE_AND_TIME literals are treated internally as data type DWORD. The time is processed in seconds and as a result can take on values from January 1, 1970 00:00 to February 7, 2106 06:28:15.

PROGRAM PLC_PRG
VAR
        dtDate : DATE_AND_TIME := DATE_AND_TIME#1996-05-06-15:36:30;
        dtDate1: DATE_AND_TIME := DT#1972-03-29-00:00:00;
        dtDate2: DATE_AND_TIME := DT#2018-08-08-13:33:20.5;

        dtEarliest : DATE_AND_TIME := DATE_AND_TIME#1970-1-1-00:00:00; // 0
        dtLatest : DATE_AND_TIME := DATE_AND_TIME#2106-2-7-6:28:15; // 4294967295
END_VAR

Use the LDATE_AND_TIME keyword (LDT) to specify a date and time.

Syntax

<date and time keyword>#<long date and time value>

<date and time keyword> : LDATE_AND_TIME | ldate_and_time | LDT | ldt
<date and time value> : <year>-<month>-<day>-<hour>:<minute>:<second>
<year> : 1677-2262
<month> : 1-12
<day> : 1-31
<hour> : 0-24
<minute> : 0-59
<second> : 0-59

LDATE_AND_TIME#2262-4-10-23:59:59.99999999

LDATE_AND_TIME literals are treated internally as data type LWORD. The time is processed in nanoseconds and can therefore have values from September 21, 1677 00:12:43.145224192 to April 11, 2262 23:47:16.854775807.

PROGRAM PLC_PRG
VAR
        ldtDate : LDATE_AND_TIME := LDATE_AND_TIME#1996-05-06-15:36:30;
        ldtDate1: LDATE_AND_TIME := LDT#1972-03-29-00:00:00;
        ldtDate2: LDATE_AND_TIME := LDT#2018-08-08-13:33:20.5;

        dtEarliest : LDT := LDT#1677-9-21-0:12:43.145224192; // 0
        dtLatest : LDT := LDT#2262-4-11-23:47:16.854775807; // = 16#7FFFFFFFFFFFFFFF
END_VAR

Use the TIME_OF_DAY keyword (TOD) to specify a time.

Syntax

<time keyword>#<time value>

<time keyword> : TIME_OF_DAY | time_of_day | TOD | tod
<time value> : <hour>:<minute>:<second>
<hour> : 0-23
<minute> : 0-59
<second> : 0.000-59.999

You can also specify fractions of a second. TIME_OF_DAY literals are treated internally as DWORD and the value is resolved in milliseconds.

PROGRAM POU
VAR
        todClockTime : TIME_OF_DAY :=  TIME_OF_DAY#15:36:30.123;
        todEarliest : TIME_OF_DAY := TIME_OF_DAY#0:0:0.000;
        todLatest : TOD := TOD#23:59:59.999;
END_VAR

Use the LTIME_OF_DAY keyword (LTOD) to specify a time.

Syntax

<time keyword>#<time value>

<time keyword> : LTIME_OF_DAY | ltime_of_day | LTOD | ltod
<time value> : <hour>:<minute>:<second>
<hour> : 0-23
<minute> : 0-59
<second> : 0.000-59.999999999

You can also specify fractions of a second. LTIME_OF_DAY literals are treated internally as LWORD and the value is resolved in nanoseconds.

PROGRAM POU
VAR
        ltodClockTime : LTIME_OF_DAY :=  TIME_OF_DAY#15:36:30.123456789;
        todEarliest : TIME_OF_DAY := TIME_OF_DAY#0:0:0;
        todLatest : TOD := TOD#23:59:59.999999999;
END_VAR

For more information, see: Data type: DATE