International teams also play friendlies, generally in preparation for the qualifying or final stages of major tournaments. This is essential, since national squads generally have much less time together in which to prepare. The biggest difference between friendlies at the club and international levels is that international friendlies mostly take place during club league seasons, not between them. This has on occasion led to disagreement between national associations and clubs as to the availability of players, who could become injured or fatigued in a friendly.
What do international leagues' friendlies happen in the middle of?
club league seasons

The four-year, full-time undergraduate program comprises the majority of enrollments at the university and emphasizes instruction in the arts and sciences, plus the professions of engineering, journalism, communication, music, and education. Although a foundation in the liberal arts and sciences is required in all majors, there is no required common core curriculum; individual degree requirements are set by the faculty of each school. Northwestern's full-time undergraduate and graduate programs operate on an approximately 10-week academic quarter system with the academic year beginning in late September and ending in early June. Undergraduates typically take four courses each quarter and twelve courses in an academic year and are required to complete at least twelve quarters on campus to graduate. Northwestern offers honors, accelerated, and joint degree programs in medicine, science, mathematics, engineering, and journalism. The comprehensive doctoral graduate program has high coexistence with undergraduate programs.
How many weeks is one academic quarter at Northwestern?
approximately 10

The Farmington Canal Trail is a rail trail that will eventually run continuously from downtown New Haven to Northampton, Massachusetts. The scenic trail follows the path of the historic New Haven and Northampton Company and the Farmington Canal. Currently, there is a continuous 14-mile (23 km) stretch of the trail from downtown, through Hamden and into Cheshire, making bicycle commuting between New Haven and those suburbs possible. The trail is part of the East Coast Greenway, a proposed 3,000-mile (4,800 km) bike path that would link every major city on the East Coast from Florida to Maine.
What historic trail does the Farmington Canal Trail follow?
New Haven and Northampton Company