Nalla Neram
Nalla neram is the correct time to do the constructive activity. Nalla neram are not many in a day; nalla neram with nalla naal is also rare the course of a month. Some times or muhurthams as they are called, are generally avoided; these times are muhurthams like rahu kalam, yamagandam etc. Some muhurthams are said to be exceptionally good (nalla neram). One example is the occurrence of abhijit nakshatram. Similarly, the Gulika kalam is the time where you can take part in an activity or execute a job that you want to repeat. Technically, Gulika kalam is a nalla neram or ketta neram, depending on the activity that you want to do.
You do not want to keep visiting the doctor again and again. For this reason, you should not go and see the doctor on Gulika time. So, get to know your nalla neram, based upon your jathagam chart; you can get to know your daily, weekly, monthly nalla neram and so on.
All favourable muhurtham times are Nalla neram. Those times are good for doing good work. Nalla neram is a time block which involves excluding rahu kalam, yamagandam, gulika kalam of the day, while including good horas of the day. Nalla neram is the filtered list of favourable times for marriage (muhurtham dates) and other auspicious activities. ePanchang provides you with your detailed nalla natkal calendar, for your instant reference.
Gulika incidentally is the son of Sani. And so, the Gulika kalam is ruled by Saturn.