Returns commercial-date week index for self (see Date.commercial):
self
Date.new(2001, 2, 3).cweek # => 5
Returns:
5402 5403 5404 5405 5406 5407
# File 'date_core.c', line 5402 static VALUE d_lite_cweek(VALUE self) { get_d1(self); return INT2FIX(m_cweek(dat)); }