Validity can start on any day you choose and then lasts for one month, e.g. from 5 September until 4 October. The exact number of days can therefore indeed vary.

So no one starts it in february……..

A month is considered to be one calendar month. In other words, the Eurail Pass will be valid for as long as the number of days of the month in which you activate it. For example, August has 31 days; if you activate your Pass on August 11th, it will be valid up to and including September 10th. That’s exactly 31 days.

If you have a Pass with a 2-month validity period it works the same way, e.g. if the Pass starts August 11th, the last day it is valid will be October 10th.

You can activate your Pass any day you want, as long as it is within 11 months of the date of purchase.