Tm tm = GetTm(tz);
wxDateTime dtMonthStart = wxDateTime(1, tm.mon, tm.year);
size_t nWeek = GetWeekOfYear(flags) - dtMonthStart.GetWeekOfYear(flags) + 1;
Tm tm = GetTm(tz);
wxDateTime dtMonthStart = wxDateTime(1, tm.mon, tm.year);
size_t nWeek = GetWeekOfYear(flags) - dtMonthStart.GetWeekOfYear(flags) + 1;