The Help example for the function TIMER is erroneous. This is the sub ExampleTimer in file:///C:/Program%20Files/LibreOffice/help/de/text/sbasic/shared/03030303.html?DbPAR=BASIC#bm_id3149346 in my Windws installation (in German). Both divisions should use the backslash instead of the slash. The present implementation yields a value for the hour which istoo great by 1, if the minute value is greater or equal 30, as a result of rounding up the result of the division. Just run the macro in the second half of an hour to see the error.
Could confirm the buggy behavior for LO Version: 7.6.0.0.alpha1+ (X86_64) / LibreOffice Community Build ID: a5c1c674e031087ef0516cebac049341dcdd2fcf CPU threads: 6; OS: Linux 5.14; UI render: default; VCL: kf5 (cairo+xcb) Locale: de-DE (de_DE.UTF-8); UI: de-DE Calc: threaded 28100 Seconds will be shown as 08:48:20, but should be 07:48:20 My system: OpenSUSE 15.4 64bit rpm Linux.
Pierre F committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/help/commit/a86b2f1aaaa7b0cceb46e7b6b6c1c58a343b5cb2 fix rounding and use Format() tdf#155654