The FIFA September international match window starts next week. All confederations (well, except OFC) are now in full swing qualifying mode for the World Cup next year in Qatar.
UEFA and CONCACAF have a one day extension to be able to accommodate 3 match days: MDs 4-6 in the UEFA groups and MDs 1-3 in the CONCACAF octogonal.
CONMEBOL also has to play three match days to catch up their postponed March match days. They even need a two day extension for that. Recent news about the English Premier League clubs refusing to release their players from countries on the COVID-19 red list could, same as in March by the way, pose a threat for especially the South American qualifiers as players from all these countries need a 10-day quarantaine when returning to England. CONMEBOL doesn't have any room in the calendar to postpone their qualifiers any further though, so it's unsure what will happen here.
CAF starts their group stage with MDs 1 and 2.
AFC starts their final group stage with the first two match days. Also the first legs of the two stage 3 play-offs in the qualification of the Asian Cup of Nations 2023 are played, with the second legs played in the October window.
The few remaining countries not playing qualification might engage in friendlies, some in small friendly tournament form.