We can configure start and stop for quickfix sessions,This can be done through settings file. We can also specify timezone to reset the session timings. This session configuration applicable to both initiator  and Acceptor  sessions.Find the below settings to configure the same.

[DEFAULT]
BeginString=FIX.4.2
CheckLatency=N
HeartBtInt=4
UseDataDictionary=Y
ReconnectInterval=4
FileStorePath=logs/store
FileLogPath=logs/log
FileStoreSync=N
SocketUseSSL=N
StartDay=Sunday
EndDay=Friday
StartTime=12:30:00
EndTime=23:30:00
TimeZone=America/New_York