How do I count the number of travel days that I need on my Pass?
A travel day is the period between 12 midnight on one day to 12 midnight of the following day (i.e. a 24 hour period). During this travel day, you can take as many trains as you wish. You can change trains, and also travel internationally, as long as you stay within these 24 hours, it will always count as one travel day.
An additional benefit is the 7PM rule: If you board a direct, overnight train after 7pm on a certain day, then only the following day (the day of arrival of the over night train) is counted as a travel day. On your Eurail Pass, you would write the day of arrival on the pass prior to boarding the overnight train.You effectively will receive 5 hours of travel for free.