# Date & Time Functions

**1 TODAY**

Returns the current computer system date. The value is updated when you reopen the document or modify the values of the document.

**Syntax**

**TODAY()**

TODAY is a function without arguments

**Example**

TODAY() returns the current computer system date.

**2 NOW**

Returns the computer system date and time. The value is updated when you recalculate the document or each time a cell value is modified.

**Syntax**

**NOW()**

NOW is a function without arguments.

**Example**

=NOW() it returns the difference between the date in cell and now. Format the result as a number.

**3 YEAR**

Returns the year as a number according to the internal calculation rules.

**Syntax**

**YEAR(Number)**

**Number** shows the internal date value for which the year is to be returned.

**Example**

=YEAR(1) returns 1899

=YEAR(2) returns 1900

=YEAR(33333.33) returns 1991

**4 MONTH**

Returns the month for the given date value. The month is returned as an integer between 1 and 12.

**Syntax**

**MONTH(Number)**

**Number** is the internal date number.

**Example**

=MONTH(NOW()) returns the current month.

=MONTH(C4) returns 7 if you enter 2000-07-07 to cell C4 (that date value might get formatted differently after you press Enter).

**5 DAY**

Returns the day of given date value. The day is returned as an integer between 1 and 31. You can also enter a negative date/time value.

**Syntax**

**DAY(Number)**

**Number** is the internal date number.

**Example**

=DAY(1) returns 31 (since LibreOffice starts counting at zero from December 30, 1899)

=DAY(NOW()) returns the current day.

=DAY(C4) returns 5 if you enter 1901-08-05 in cell C4 (the date value might get formatted differently after you press Enter).

**6 DATE**

This function calculates a date specified by year, month, day and displays it in the cell’s formatting. The default format of a cell containing the DATE function is the date format, but you can format the cells with any other number format.

**Syntax**

DATE(Year; Month; Day)

**Year** is an integer between 1583 and 9957 or between 0 and 99.

**Month** is an integer indicating the month.

**Day** is an integer indicating the day of the month.

If the values for month and day are out of bounds, they are carried over to the next digit. If you enter =DATE(00;12;31) the result will be 2000-12-31. If, on the other hand, you enter =DATE(00;13;31) the result will be 2001-01-31.

**Example**

=DATE(00;1;31) yields 1/31/00 if the cell format setting is MM/DD/YY.

**7 DATEDIF**

This function returns the number of whole days, months or years between Start date and End date.

**Syntax**

DATEDIF(Start date; End date; Interval)

**Start date** is the date from when the calculation is carried out.

**End date** is the date until the calculation is carried out. End date must be later, than Start date.

**Interval** is a string, accepted values are “d”, “m”, “y”, “ym”, “md” or “yd”.

Value for “Interval” | Return value |

“d” | Number of whole days between Start date and End date. |

“m” | Number of whole months between Start date and End date. |

“y” | Number of whole years between Start date and End date. |

“ym” | Number of whole months when subtracting years from the difference of Start date and End date. |

“md” | Number of whole days when subtracting years and months from the difference of Start date and End date. |

“yd” | Number of whole days when subtracting years from the difference of Start date and End date. |

**Example**

Birthday calculation. A man was born on 1974-04-17. Today is 2012-06-13.

=DATEDIF(“1974-04-17″;”2012-06-13″;”y”) yields 38.

=DATEDIF(“1974-04-17″;”2012-06-13″;”ym”) yields 1.

=DATEDIF(“1974-04-17″;”2012-06-13″;”md”) yields 27.

So he is 38 years, 1 month and 27 days old.

=DATEDIF(DATE(1974,4,17);”2012-06-13″;”m”) yields 457, he has been living for 457 months.

=DATEDIF(“1974-04-17″;”2012-06-13″;”d”) yields 13937, he has been living for 13937 days.

=DATEDIF(“1974-04-17″;DATE(2012;06;13);”yd”) yields 57, his birthday was 57 days ago.

**8 ISOWEEKNUM**

ISOWEEKNUM calculates the week number of the year for the internal date value.

**Syntax**

ISOWEEKNUM(Number)

**Number** is the internal date number.

**Example**

=ISOWEEKNUM(DATE(1995;1;1)) returns 52. Week 1 starts on Monday, 1995-01-02.

=ISOWEEKNUM(DATE(1999;1;1)) returns 53. Week 1 starts on Monday, 1999-01-04.

**9 MINUTE**

Calculates the minute for an internal time value. The minute is returned as a number between 0 and 59.

**Syntax**

MINUTE(Number)

**Number**, as a time value, is a decimal number where the number of the minute is to be returned.

**Example**

=MINUTE(8.999) returns 58

=MINUTE(8.9999) returns 59

=MINUTE(NOW()) returns the current minute value.

**10 SECOND**

Returns the second for the given time value. The second is given as an integer between 0 and 59.

**Syntax**

SECOND(Number)

**Number**, as a time value, is a decimal, for which the second is to be returned.

**Example**

=SECOND(NOW()) returns the current second

=SECOND(C4) returns 17 if contents of C4 = 12:20:17.

**11 HOUR**

Returns the hour for a given time value. The hour is returned as an integer between 0 and 23.

**Syntax**

HOUR(Number)

**Number**, as a time value, is a decimal, for which the hour is to be returned.

**Example**

=HOUR(NOW()) returns the current hour

=HOUR(C4) returns 17 if the contents of C4 = 17:20:00.

**12 DAYS**

Calculates the difference between two date values. The result returns the number of days between the two days.

**Syntax**

DAYS(Date2; Date1)

**Date1** is the start date, **Date2** is the end date. If **Date2** is an earlier date than **Date1** the result is a negative number.

**Example**

=DAYS(NOW();”2010-01-01″)) returns the number of days from January 1, 2010 until today.

=DAYS(“1990-10-10″;”1980-10-10”) returns 3652 days.

**13 WEEKDAY**

Returns the day of the week for the given date value. The day is returned as an integer between 1 (Sunday) and 7 (Saturday) if no type or type=1 is specified. For other types, see the table below.

**Syntax**

WEEKDAY(Number; Type)

**Number**, as a date value, is a decimal for which the weekday is to be returned.

**Type** is optional and determines the type of calculation.

Type | Weekday number returned |

1 or omitted | 1 (Sunday) through 7 (Saturday). For compatibility with Microsoft Excel. |

2 | 1 (Monday) through 7 (Sunday). |

3 | 0 (Monday) through 6 (Sunday) |

11 | 1 (Monday) through 7 (Sunday). |

12 | 1 (Tuesday) through 7 (Monday). |

13 | 1 (Wednesday) through 7 (Tuesday). |

14 | 1 (Thursday) through 7 (Wednesday). |

15 | 1 (Friday) through 7 (Thursday). |

16 | 1 (Saturday) through 7 (Friday). |

17 | 1 (Sunday) through 7 (Saturday). |

Example

=WEEKDAY(“2000-06-14”) returns 4 (the Type parameter is missing, therefore the standard count is used. The standard count starts with Sunday as day number 1. June 14, 2000 was a Wednesday and therefore day number 4).

=WEEKDAY(“1996-07-24”;2) returns 3 (the Type parameter is 2, therefore Monday is day number 1. July 24, 1996 was a Wednesday and therefore day number 3).

=WEEKDAY(“1996-07-24”;1) returns 4 (the Type parameter is 1, therefore Sunday is day number 1. July 24, 1996 was a Wednesday and therefore day number 4).

=WEEKDAY(“2017-05-02”;14) returns 6 (the Type parameter is 14, therefore Thursday is day number 1. May 2, 2017 was a Tuesday and therefore day number 6)

=WEEKDAY(NOW()) returns the number of the current day.

** 14 TIME**

TIME returns the current time value from values for hours, minutes and seconds. This function can be used to convert a time based on these three elements to a decimal time value.

**Syntax**

TIME(Hour; Minute; Second)

Use an integer to set the **Hour**.

Use an integer to set the **Minute**.

Use an integer to set the **Second**.

**Example**

=TIME(0;0;0) returns 00:00:00

=TIME(4;20;4) returns 04:20:04

**15 TIMEVALUE**

TIMEVALUE returns the internal time number from a text enclosed by quotes and which may show a possible time entry format.

The internal number indicated as a decimal is the result of the date system used under LibreOffice to calculate date entries.

If the text string also includes a year, month, or day, TIMEVALUE only returns the fractional part of the conversion.

**Syntax**

TIMEVALUE(“Text”)

**Text** is a valid time expression and must be entered in quotation marks.

**Example**

=TIMEVALUE(“4PM”) returns 0.67. When formatting in time format HH:MM:SS, you then get 16:00:00.

=TIMEVALUE(“24:00”) returns 0. If you use the HH:MM:SS time format, the value is 00:00:00.