Question: When do the days of arrival and departure start and end when one arrives at a place?
ANSWER
Islamically, a day starts when imsak time starts and lasts until the imsak time of the following day.

For example, if one arrives in Istanbul when the adhan for Salat al-Fajr is being called out after imsak time, that day is not counted because it is considered the day of arrival. If one arrives there before imsak time, the day after imsak time will not be counted as the day of arrival. If one departs from there after imsak time, that day will be counted as the day of departure.

In brief, if one arrives at a place when the sun is rising, that day is not counted as a day because it is the day of arrival. If one departs from there after imsak time, say, when the sun is rising, that day is not counted, either.

Question: It is written in the book Se'adet-i Ebediyye, "In the Hanafi Madhhab, if one stays at a place for 15 days, excluding the days of departure and arrival, one will be a muqim there." If one goes to a city that is at a safar distance to stay there for 15 days, will one be a muqim or a safari there?
ANSWER
One will be a safari there because a day is divided into 24 hours. A day, Islamically, starts when imsak time starts. If one arrives at a place during the time for, for example, Salat az-Zuhr or Salat al-Isha, that day is not counted as a day. If one departs from there during the time for, for example, Salat az-Zuhr or Salat al-Isha, that day is not counted as a day, either. In this case, one will stay there for 13 days in total as the days of arrival and departure will not be taken into account. One will be a safari there as one will not stay for 15 days.