Islam works on the lunar year, which is shorter than the solar year, and so everything timed by it appears to move forward by about eleven days annually when compared to the solar calendar. This means that Ramadan will be moving through the Christian season of Lent for the next few years.
Both have in common the practice of fasting but with significant differences in approach and rigour. They share much more when we think of the additional dimensions to both seasons beyond physical fasting, but each has particular aspects not shared by the other.
The following article explores some of these similarities and differences: Lent and Ramadan – PDF