The program Atomic Webserver 3 uses _DateUTC() and on Windows (x86 and x64 - assembler backend) PB6.11 the imported procedure fails and returns a pointer or some other unusable value when called.
Would be nice if it could be used again in the next PB version as I started to play around with UTC dates and I'd like to write something that needs precise UTC date/time

It still works fine on the Linux versions I tested and on the C backend (but it makes it more complicated to select/unselect the compiler in the options manually for every compilation when transferring/opening the source on the other OS'es IDE's - the Linux IDE's can't find the selected compiler).
CompilerSelect #PB_Compiler_OS ;for compatiblity with 6.04lts
CompilerCase #PB_OS_Windows
CompilerIf #PB_Compiler_32Bit
ImportC ""
_DateUTC.q(t = #Null) As "_time"
EndImport
CompilerElse
ImportC ""
_DateUTC.q(t = #Null) As "time"
EndImport
CompilerEndIf
CompilerCase #PB_OS_Linux
Procedure.q _DateUTC()
ProcedureReturn time_(#Null)
EndProcedure
CompilerCase #PB_OS_MacOS
ImportC ""
CFAbsoluteTimeGetCurrent.d()
EndImport
Procedure.q _DateUTC()
ProcedureReturn CFAbsoluteTimeGetCurrent() + Date(2001, 1, 1, 0, 0, 0)
EndProcedure
CompilerEndSelect