Is this what you mean?

=HVIS(OG(ELLER(ER.TOM(Uge1!D4);ER.TOM(Uge1!E4)),Uge1!F4=Rulleplan!D4);"";
HVIS(MINUT(Uge1!D4)>0;TIME(Uge1!D4)&"."&MINUT(Uge1!D4);TIME(Uge1!D4))&"-"&HVIS(MINUT(Uge1!E4)>0;TIME(Uge1!E4)&"."&MINUT(Uge1!E4);TIME(Uge1!E4))&" "&Uge1!F4)