1. // ISO-8601, Europe
    2. moment.updateLocale("en", { week: {
    3.   dow: 1, // First day of week is Monday
    5. }});
    7. // US, Canada
    8.   dow: 0, // First day of week is Sunday
    9.   doy: 6  // First week of year must contain 1 January (7 + 0 - 1)
    10. }});
    12. // Many Arab countries
    14.   dow: 6, // First day of week is Saturday
    15. }});
    17. // Also common
    18. moment.updateLocale("en", { week: {
    19.   dow: 1, // First day of week is Monday
    20.   doy: 7  // First week of year must contain 1 January (7 + 1 - 1)
    21. }});