id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
6345	"displayUnit of inverse time ""d-1"", ""h-1"", ''min-1"" not working"	pierre.haessig@…	Martin Sjölund	"Dear OM devs,

With OM 1.16.2, I can't get variables representing a rate in per second (""s-1"") to display as per day, per hour or per minute (i.e. `unit=""s-1""` and `displayUnit=""d-1""` or ""h-1"", ""min-1""). See example model attached.

I've checked that the `displayUnit=""d""` for a time works. For a rate, `displayUnit=""ks-1""` (per 1000 seconds) also works fine, i.e. displays the value multiplied by 1000. So the problem does not concerns the conversion of all units with a -1 exponent.

I've found the implementation of the ""day"" unit was discussed in issue #2250 (https://trac.openmodelica.org/OpenModelica/ticket/2250#comment:27) and is visible in the code at https://github.com/OpenModelica/OpenModelica/blob/master/OMCompiler/Compiler/runtime/unitparser.cpp#L1152.

About the application: I gave students a modeling project about [https://www.lewuathe.com/covid-19-dynamics-with-sir-model.html/ SIR epidemy models]. Quite fashionable these days! I think infection rates are often given per day.

Best,
Pierre"	defect	reopened	normal		OMEdit	1.16.2