HOUR in Collabora Office Calc: Extract Clock Hours Without Losing Duration Context

• Introduced: original Collabora release and launch date are not established by the sources reviewed.
• Availability: documented in Collabora Office 26.04 help, scoped to that desktop-help release.
• Platform scope: separately deployed Online and mobile versions are not inferred from desktop documentation.
• Checked: October 14, 2026. Direct documentation and independent calendar/time controls; no native Collabora test was performed.

=HOUR(number)

The argument is an internal numeric time value, including a timestamp’s fractional-day part. The reference documents the 0–23 range and illustrates 17:20 returning 17. These examples construct times explicitly with TIME.

Display HOUR’s result as a plain number. A time format applied to the extracted integer 17 would interpret a different numeric quantity, rather than restore the original 17:20 clock value.

=HOUR(TIME(0;0;0))
=HOUR(TIME(9;30;0))
=HOUR(TIME(17;20;0))
=HOUR(TIME(23;59;59))

Expected results are 0, 9, 17 and 23. Minutes and seconds do not become a fractional HOUR result; the function returns the hour component as an integer.

For 09:30, the hour component is 9 while decimal hours since midnight are 9.5. Dividing or multiplying the original time fraction answers the latter question.

=HOUR(DATE(2026;10;14)+TIME(17;20;0))

Expected result: 17. The calendar date is part of the timestamp, but HOUR extracts only the clock-hour component. A timestamp on another date at 17:20 has the same extracted hour.

Grouping records by HOUR therefore combines equal clock hours across days unless a date key is retained too. Use the grouping that the report actually intends.

A numeric value of 1.5 days represents 36 elapsed hours. Compare:

=HOUR(1.5)
=1.5*24

Expected results are 12 and 36. HOUR extracts the 12-hour clock portion after a whole day; multiplication converts the entire day quantity to hours.

A result of 12 is not evidence that 24 hours vanished from the stored input. The function deliberately returns a bounded component, not a duration total.

Put times 08:59:00, 09:00:00, 16:59:00 and 17:00:00 in A2:A5 using TIME formulas. For a stated time-of-day window beginning 09:00 and ending before 17:00:

=AND(HOUR(A2)>=9;HOUR(A2)<17)

Filled down, expected flags are FALSE, TRUE, TRUE, FALSE. This whole-hour policy works because the boundaries fall on full hours. It does not validate an employment schedule, holiday calendar or a partial-hour closing time.

For a 16:30 cutoff, compare the original time value with TIME(16;30;0) instead of assuming the hour component alone can distinguish 16:15 from 16:45.

For A2 containing =TIME(17;20;4):

=HOUR(A2)*3600+MINUTE(A2)*60+SECOND(A2)

Expected total: 62404 seconds since midnight. The same ordinary whole-second control can be checked with A2*86400.

The component reconstruction is not a universal lossless conversion for fractional seconds: Collabora’s SECOND rounds to a nearest second. Keep the original fraction when subsecond precision matters.

=TIME(HOUR(A2);0;0)

For the 17:20:04 control, expected clock result is 17:00:00. This deliberately drops minutes and seconds and returns a time-only value. It does not preserve the date of a larger timestamp unless that date is added separately.

Check that the source is a numeric time or timestamp, rather than the plain number 17 intended to mean 17 hours. Numeric spreadsheet time is measured in days, so 17 by itself is not a time-construction instruction.

The direct reference does not establish every text, blank, negative-serial or error-code outcome. The documented date/time model does not encode timezone information; HOUR cannot infer a local zone from a clock value. See TIME for explicit construction and MINUTE for the next component.

• Collabora Office 26.04: HOUR.
• Collabora date/time model and date bases.
• Editorial testing standards.

The dedicated product help was read directly. Calendar and numeric outputs are independently calculated expectations, with stated parsing and boundary limits. No native runtime or universal cross-deployment certification is claimed.