Rahu kalam calculation- why is it not the 1/8th of daylight in J hora?

[Guest guest]

Namasthae, Isn't it true that Raahu Kaalam is assumed to be a particular 1/8th of daylight, like the last eighth for a Sunday? I see that for Michigan, day after tomorrow- Sunday the 4th april 2010, Raahu Kaalam reads as 17:44 to 19:14, whereas the sun sets at 19:57, all per J hora-4 latest version (sunrise at 7:14). Is it that only 12 hours from sunrise is considered as day time? Let me hasten to add that the intent here is to learn and not fault-finding.Also, any pointers regarding Gulika period? In some communities, they use this time slot for moving deceased folks from home (trip for cremation/burial), some others avoid exactly this time slot for that activity; some others even perform wedding during Gulika period, not as a

preference but out of indifference to this time slot!Thanks in advance for response.Sree