The last time the UK singles and album charts switched their date of publication was in October 1987. In what was hailed as a revolution in computer technology (but which in actual fact was simply due to all shops now reporting sales via the Epson terminals installed in chart return outlets) it was no longer necessary to wait until Tuesday lunchtime to hear the new singles chart. The Radio One Top 40 show on Sunday evenings was now the place to be, the latest sales information available less than 12 hours after the shops had closed. At the time it was pretty revolutionary stuff.

It should be noted however that this was merely a change in publication date, moving it up two days. The actual survey itself remained Monday through Saturday (Sunday trading laws at the time meant few if any outlets could sell music on that day). The only noticeable consequence was that the Radio One show, traditionally the broadcast outlet of record, skipped a week so the show on October 4th 1987 instead of counting down the singles chart first revealed on Tuesday, September 29th ended up revealing the brand new countdown for Week Ending October 10th. It meant that Pump Up The Volume's first week at the top was never to be broadcast.

The last time the survey period was changed was actually just prior to that, for a brief period at the start of 1982 when then compilers BMRB changed from Monday-Saturday to Friday-Thursday to sidestep the problem of the manually compiled shop diaries from the weekend being delayed in the post. The only problem was the labels hated it as it meant that the impact of Top Of The Pops appearances was delayed for a full week. The arrival of Gallup and their computer terminals at the start of 1983 put an end to postal issues forever.

Next month however there is to be a genuine change. As previously documented the British charts are to move their date of publication to coincide with the introduction of Global Release Day, or as it is now being branded New Music Friday which will see music released in key markets on the same day globally. Until now it has been a matter of guesswork as to how and when this change will be made, although listeners to this week's podcast will have heard me speculating wildly about what is to take place.

Now all can be revealed, and this is how it will work:

Week 27 will be the final Sunday-Saturday chart survey. It will run from June 28th to July 4th. The last ever Sunday afternoon Radio One chart show will announce this countdown on Sunday, July 5th.

Week 28 will be a truncated five-day survey, gathering sales from Sunday, July 5th to Thursday, July 9th. It will be the subject of the first-ever Friday afternoon chart rundown on Radio One, broadcast on July 10th.

That just so happens to be the first-ever Global Rele New Music Friday and handily the UK charts are now nicely in sync with this. Week 29 will, therefore, survey Friday, July 10th to Thursday, July 16th ready for broadcast on Friday 17th. And all will be well with the world.

Finally, you will note this impacts the publication of Music Week which has been delivered to subscribers on Thursdays and hits the streets on Fridays since 2011. They are to revert back to Monday publication to remain the journal of record for the music charts, the first such issue landing on Monday, July 13th.

Indeed the only question left unanswered is that of the dating convention for each music chart. For consistency, starting with the original British Hit Singles book back in 1977, chart reference books have used the Saturday cover date of the corresponding issue of Music Week. It is a convention I follow, hence all my columns, podcasts and books refer to charts of Week Ending xxx - ie the end of the week that the chart is announced. Technically that link between Music Week and the date of the chart ended in August 2011 when the new owners of the magazine began branding it with the street date, a Friday rather than a Saturday, but the convention has stuck.

Now that will indeed have to change. A Week Ending date of Saturday will actually mean the chart is 'dated' after its successor is unveiled. I've asked the Official Charts Company if they have an official view on the subject but am still awaiting a formal reply. That does imply nobody has actually thought it through yet.

My personal view is that it is probably now appropriate to switch to referring to singles charts from the date they become valid, and for consistencies sake, this can still be a Saturday. It will simply mean there will be two charts for July 11th, the Week Ending chart first revealed the previous Sunday and the new Week Commencing chart unveiled the previous day. This would actually align it with the historical archive on the Official Charts Company website which currently presents archive charts as being dated from their Sunday of publication - even though this is not the case for those tables pre-October 1987. I get more grumpy emails from people about that issue than anything else at present. [As it eventually turned out, common sense prevailed and we just switched the "week ending" dates of charts to the Thursday.