Proposed changes to spreadsheet functions YEAR, MONTH, DAY, HOUR, MINUTE, SECOND and other related

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• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Fixed
• Affects Version/s: ODF 1.2
• Fix Version/s:
• Component/s: None
• Labels:
None
• Environment:

OpenFormula

• Resolution:
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Updated on 11/Sep/23 as resolved, but (25/Sep/23) subject to further discussion:

The following text changes, previously resolved, have been rejected following further discussion. A new resolution for this issue is to be proposed.

6.10.5 DAY

Summary: Returns the day from a date.

Syntax: DAY( DateParam D [ ; Logical Truncate = TRUE ] )

Returns: Integer

Constraints: None

Semantics: If Truncate is FALSE, returns the day portion of D after first rounding (using ROUND()) to the nearest second. If Truncate is TRUE, returns the day portion of D without first rounding to the nearest second.

6.10.10 HOUR

Summary: Extracts the hour (0 through 23) from a time.

Syntax: HOUR( TimeParam T [ ; Logical Truncate = TRUE ] )

Returns: Integer

Constraints: None

Semantics: Extract from T the hour value, 0 through 23, as per a 24-hour clock.

If Truncate is TRUE, this is equal to:

DayFraction = (T - INT(T))

HourFraction = INT(DayFraction * 60)

If Truncate is FALSE, this is equal to:

Second = MOD(ROUND(T * 86400) ; 60)

Minute = (MOD(ROUND(T * 86400) ; 3600) - Second) / 60

Hour = (MOD(ROUND(T * 86400) ; 86400) - Minute * 60 - Second) / 3600

See also MONTH 6.10.13, DAY 6.10.5, MINUTE 6.10.12, SECOND 6.10.16, MOD 6.16.42, ROUND 6.17.5

6.10.12 MINUTE

Summary: Extracts the minute (0 through 59) from a time.

Syntax: MINUTE( TimeParam T [ ; Logical Truncate = TRUE ] )

Returns: Integer

Constraints: None

Semantics: Extract from T the minute value, 0 through 59, as per a clock.

If Truncate is TRUE, this is equal to:

DayFraction = (T - INT(T))

HourFraction = (DayFraction * 24 - INT(DayFraction * 24))

Minute = INT(HourFraction * 60)

If Truncate is FALSE, this is equal to:

Second = MOD(ROUND(T * 86400) ; 60)

Minute = (MOD(ROUND(T * 86400) ; 3600) - Second) / 60

See also MONTH 6.10.13, DAY 6.10.5, HOUR 6.10.10, SECOND 6.10.16, MOD 6.16.42, ROUND 6.17.5

6.10.13 MONTH

Summary: Extracts the month from a date.

Syntax: MONTH( DateParam D [ ; Logical Truncate = TRUE ] )

Returns: Integer

Constraints: None

Semantics: If Truncate is FALSE, returns the month portion of D after first rounding (using ROUND()) to the nearest second. If Truncate is TRUE, returns the month portion of D without first rounding to the nearest second.

6.10.16 SECOND

Summary: Extracts the second (the integer 0 through 59) from a time. This function presumes that leap seconds never exist.

Syntax: SECOND( TimeParam T [ ; Logical Truncate = TRUE ] )

Returns: Integer

Constraints: None

Semantics: Extract from T the second value, 0 through 59, as per a clock.

If Truncate is TRUE, this is equal to:

DayFraction = (T - INT(T))

HourFraction = (DayFraction * 24 - INT(DayFraction * 24))

MinuteFraction = (HourFraction * 60 - INT(HourFraction * 60))

Second = INT(MinuteFraction * 60)

If Truncate is FALSE, this is equal to:

Second = MOD(ROUND(T * 86400) ; 60)

See also MONTH 6.10.13, DAY 6.10.5, HOUR 6.10.10, MINUTE 6.10.12, MOD 6.16.42, ROUND 6.17.5

6.10.23 YEAR

Summary: Extracts the year from a date given in the current locale of the evaluator.

Syntax: YEAR( DateParam D [ ; Logical Truncate = TRUE ] )

Returns: Integer

Constraints: None

Semantics: If Truncate is FALSE, returns the year portion of D after first rounding (using ROUND()) to the nearest second. If Truncate is TRUE, returns the year portion of D without first rounding to the nearest second.

If a year is given as a two-digit number, as in "05-21-15", then the year returned is either 1915 or 2015, depending upon the break point in the calculation context. In an OpenDocument document, this break point is determined by HOST-NULL-YEAR.

Evaluators shall support extracting the year from a date beginning in 1900. Three-digit year numbers precede adoption of the Gregorian calendar, and may return either an Error or the year number. Four-digit year numbers preceding 1582 (inception of the Gregorian Calendar) may return either an Error or the year number. Four-digit year numbers following 1582 should return the year number.

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Description

Email from Mike Kaganski, 15 September 2020 reads:

As mentioned in [1], there is a problem in the OASIS OpenFormula standard (as of v.1.3 [2]). The spreadsheet functions YEAR, MONTH, DAY, HOUR, MINUTE are defined in such a way that for any given value of time, they discard fractions of respective time part: e.g., MINUTE would only return whole number of minutes contained in the parameter, discarding any fraction of a minute, no matter how close it is to 1. On the other hand, spreadsheet function SECOND is defined to round the number of seconds in minute fraction, thus it may return a number that is greater by 1 compared to the whole number of seconds actually contained in the minute fraction.

Furthermore, SECOND is defined to return 0 through 59 (never 60), but to use formula equivalent to ROUND(MinuteFraction * 60). Here is the first minor inconsistency: ROUND(MinuteFraction * 60) results in numbers 0 through 60, not through 59.

It is impossible to modify the definition of SECOND to return 0 through 60, because it would then become inconsistent with other spreadsheet software, introducing major interoperability problems. Correcting the equivalent formula to result in 0 through 59, like "MOD(ROUND(MinuteFraction * 60), 60)", brings us to the next inconsistency:

ÂÂÂ For all values of TimeParam T which have (MinuteFraction * 60) between 59.5 and 60.0, the set of functions:

Â ÂÂ ÂÂ =YEAR(T) &""& MONTH(T) &""& DAY(T) &" "& HOUR(T) &":"& MINUTE(T) &":"& SECOND(T)

ÂÂÂ results in an ISO date-time string that is off by ~1 minute (actually, exactly by value of (MinuteFraction * 60) seconds).

This happens because value returned by SECOND will be 0 (zero), as if the next minute has already started, while all other functions return values of the minute, hour, day, ... that are still active for T.

For instance, for T corresponding for 2020-09-15 15:23:59.60, the result of the mentioned formula would be "2020-9-15 15:23:0".

It is impossible to change definition of SECOND to discard fraction of a second (for consistency with other functions), because then it would again be inconsistent with other spreadsheet software. So the only solution is to re-define the other functions to be consistent with (improved) SECOND definition, like this:

ÂÂÂ * Proposed improvement for SECOND(TimeParam T): Second=MOD(ROUND(T*86400);60)

ÂÂÂ * Proposed change for MINUTE(TimeParam T): Minute=(MOD(ROUND(T*86400);3600)-SECOND(T))/60

ÂÂÂ ... etc.

This would not only make the functions consistent within the standard, but also with other spreadsheet software.

Attachments

1. NewProposal SECOND function.odt
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• Assignee:
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Reporter:
Patrick Durusau
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