Is It Needed to Normalize of Date Columns I am designing a small database with relatively small data. The question is about normalization of Datetime columns. The dates of year occured many times and should I create a Days tables with a Primary Key or let it occure in tgw Main table ignoring Norm rules. (Please ignore the first column named City, see it as CityID)


The main table will be truncated once a month and only the datas for the next month will be stored per City.
The db schema highly robust so will not change. Also there is no need to add a table in a relation with Date column or Dates table.

+--------+------------+------+---------+-------+------+---------+------+
| City   | Date       | Fajr | Sunrise | Dhuhr | Asr  | Maghrib | Isha |
+--------+------------+------+---------+-------+------+---------+------+
| Adana  | 01.01.2015 | 3:49 | 5:31    | 12:36 | 4:25 | 7:39    | 9:15 |
| Ankara | 01.01.2015 | 3:45 | 5:34    | 12:45 | 4:40 | 7:56    | 9:39 |
| Konya  | 01.01.2015 | 3:57 | 5:41    | 12:47 | 4:38 | 7:52    | 9:30 |
| Adana  | 13.01.2015 | 3:49 | 5:31    | 12:36 | 4:25 | 7:39    | 9:15 |
| Ankara | 13.01.2015 | 3:45 | 5:34    | 12:45 | 4:40 | 7:56    | 9:39 |
| Konya  | 13.01.2015 | 3:57 | 5:41    | 12:47 | 4:38 | 7:52    | 9:30 |
+--------+------------+------+---------+-------+------+---------+------+



You see the dates are occuring. Should the new design is like this?

+-------+------------+
| DayID | Date       |
+-------+------------+
| 1001  | 01.01.2015 |
| 5003  | 13.01.2015 |
+-------+------------+

+--------+-------+------+---------+-------+------+---------+------+
| City   | DayID | Fajr | Sunrise | Dhuhr | Asr  | Maghrib | Isha |
+--------+-------+------+---------+-------+------+---------+------+
| Adana  | 1001  | 3:49 | 5:31    | 12:36 | 4:25 | 7:39    | 9:15 |
| Ankara | 1001  | 3:45 | 5:34    | 12:45 | 4:40 | 7:56    | 9:39 |
| Konya  | 1001  | 3:57 | 5:41    | 12:47 | 4:38 | 7:52    | 9:30 |
| Adana  | 5003  | 3:49 | 5:31    | 12:36 | 4:25 | 7:39    | 9:15 |
| Ankara | 5003  | 3:45 | 5:34    | 12:45 | 4:40 | 7:56    | 9:39 |
| Konya  | 5003  | 3:57 | 5:41    | 12:47 | 4:38 | 7:52    | 9:30 |
+--------+-------+------+---------+-------+------+---------+------+
There is not a real need to have a dates table. However, there are some cool things you can do with a dates table such as add columns to that table that have different pieces of information about that day such as holidays or weekends or week of the year, etc. Instead of doing a function to get that information.