A two-and-a-half-month window for the IPL every year, and home-season windows for the Hundred and the BBL respectively in England and Australia's schedules, affirm the growing primacy of franchise T20 leagues in the international cricket calendar.

A near-final draft of the ICC's latest Future Tours Programme (FTP), accessed by ESPNcricinfo, lays out the international cricket due to be played by the 12 Full Members between May 2023 and April 2027. It is built primarily on two cycles of the World Test Championship (WTC), a host of ICC events and plenty of bilateral white-ball cricket. But it is the unmarked gaps in the calendar that tell the real story.

It isn't only the BCCI who has its own T20 window. The ECB and CA have built in smaller windows during their home seasons for their premier white-ball events - the Hundred and the BBL respectively.

Unlike the IPL, however, the Hundred and BBL windows don't bring international cricket to a halt. They squeeze space out of the calendars of England and Australia, who have previously played both tournaments alongside international games.

Every English summer in this draft FTP, for example, a three-week window across July and August is clear of any international cricket. That is, presumably, to allow England's marquee white-ball players more time in their marquee white-ball tournament, something the ECB has pushed for in scheduling discussions for this FTP. In the first season of the Hundred, some of England's biggest names, such as Ben Stokes, Jos Buttler and Joe Root, only turned out for two games, because of international commitments.

The 2023-24 season is likely to be complicated by the ODI World Cup in India, with the FTP showing Australia remain there for five T20Is, meaning the home summer is not scheduled to begin until the second week of December. The West Indies visit is also under the final year of the current broadcast deal which would come with an agreed number of matches.

The following two seasons appear more clear for the BBL although there is an away Test series to Sri Lanka from late January in 2025. Another squeeze is on the cards in 2026-27, when a five-match Test tour of India is earmarked from mid-January.

Other members have also made space for their T20 leagues. The CPL's August-September window is all but set, though there's only ever been a handful of international cricket played in the Caribbean in those months. Bangladesh have kept January free for the BPL in each year of this FTP.

Cricket South Africa's (CSA) third attempt at a franchise T20 league is set to launch in January 2023. In the draft of the new FTP, they have a window clear of international cricket in January 2025 and January 2026. But they have only a two-week break between the end of a potential visit by India (from mid-December to mid-January) in the 2023-24 season and a trip to New Zealand. And in 2026-27, England are scheduled to visit for a full tour that lasts until February 2027; both the India and England visits are important for CSA but both could impact their T20 league.

South Africa's league could clash with the UAE's International League T20 (ILT20), which is also hoping to create a window in January-February. Those months have been considered prime months for cricket in several countries in Asia and the southern hemisphere.

The PSL's challenge is more complex. Across the FTP, the PCB has left windows open for when the league is likely to be played: in February-March (2023), January-February (2024) and December-January (2026-27). That might be a consequence of not wanting to clash with the Islamic month of Ramzan, which is on the lunar calendar and starts ten days earlier every year. As much as anything, avoiding the month is a commercial decision: Ramzan is a period of heavy ad-spends for many brands, which impacts money spent on the PSL.

The real crunch for the PSL, however, is the 2024-25 season. A home WTC series with England is followed by a succession of series in the southern hemisphere: in Australia, Zimbabwe, South Africa and New Zealand. That takes them to the start of February 2025, when there is a short ODI tri-series scheduled with New Zealand and South Africa at home.

Immediately after, Pakistan host the Champions Trophy, their first ICC event since the 1996 World Cup. That is due to end on March 9, by which time Ramzan will already have begun. After that is the only window available for the PSL (unless the white-ball only tours to Australia and Zimbabwe earlier are scrapped), meaning it not only takes place during Ramzan but could also potentially become the first league to go head-to-head, for some part, with the IPL.

A number of tours in this draft of the FTP are red-circled, an indication that some element of a tour has not yet been finalised. Those may be firmed up over the course of the next week or so, and a final draft is expected to be published by the ICC after its Annual General Meeting (AGM) which takes place on July 25 and 26 in Birmingham.