When you are traveling from the east to the west and you cross the international dateline do you repeat a day or lose a day?

In this case you are loosing a day, or in other words, adding 24 hours to your watch.

Did you know that one country, Kiribati,  that lies around the international Dateline used to have the problem that the two parts of the country had similar time, but different days? The offices could only communicate on 3 days of the week, as during the rest of the time at least one part of the country had a weeked. This was changed in 1995 and now the whole of Kiribati lies on the west side of the line and also has the most advanced time on earth.