Not a Saturday. Mr Federer, the King of Grass, the Grand Vizier of Wimbledon, does Sundays. He is particularly adept at labouring on the Lord's Day in the second week of Wimbledon and not averse to turning up on the Sunday the next year to tell the world how he won the tournament.
But he strolled into the media room at the All England Club on a sunny Saturday almost as a matter of duty. The sovereign must convey his message to his public and Federer believes - how he believes - that the champion's press conference to be conducted today by one Andrew Barron Murray may, in fact, be his engagement next year.
There is much to admire in the greatest tennis player of all time. The purists once salivated at his backhand, acclaimed American novelist David Foster Wallace wrote a eulogy to Federer's tennis as an expression of human beauty, and, more prosaically but no less sincerely, the bookmakers once priced the Swiss player at such tight odds that one suspected they were pricing up the possibility of the sun coming up tomorrow.
But that was then, and this is now. The fading of greatness can sometimes not quite be caught by the eye. It is, though, reflected in the black and white of the honours board.
Federer has not won a Grand Slam since he beat Murray at Wimbledon two years ago. This may not be a long time for mere mortals, but it is an aeon for a sporting god.
His casual dismissal of the Scot in four sets was almost routinely brilliant and brought up his 17th Grand Slam, a record. Since then he has suffered a drought in slams.
His record since winning his 17th major championship runs as follows: 2012 US Open quarter-final (defeated by Tomas Berdych), 2013 Australian Open semi-final (defeated by Murray), 2013 French Open quarter-final (Jo Wilfried-Tsonga), 2013 Wimbledon second round (Sergiy Stakhovsky), 2013 US Open fourth round (Tommy Robredo), 2014 Australian Open semi-final (Rafael Nadal) and 2014 French Open fourth round (Ernests Gulbis).
It is not the imprint of a king but merely that of a gifted member of the court. And Federer was never made for that.
He arrives in London in search of his eighth Wimbledon title with the recent addition of a set of twin boys to add to his set of twin girls. He is now 32, has suffered from back problems, and, in the wake of the Stakhovsky defeat, has switched to a bigger racquet and to another coach in Stefan Edberg.
This much has changed, but Federer remains in essence the personality who won five consecutive Wimbledon championships from 2003, adding his two others in 2009 and 2012. He is smooth, articulate and relaxed off court, but even on a Saturday, when the noise of battle is still far off, Federer exudes the sort of focus only champions have.
There may be doubters about his ability to win another Wimbledon. They do not include Federer.
He has been coming to this patch of south London since he competed as a junior in 1998. This is his playground, his fiefdom and his favourite spot in the sporting world.
He believes Murray could defend his title, he knows Rafael Nadal may be vulnerable in the early rounds but would be formidable in the latter stages, and he respects Novak Djokovic.
But Federer is here to win. "Sometimes I was the big favourite, sometimes one of the favourites," he says of Wimbledons past.
And he says of his mindset coming to Wimbledon 2014: "In terms of that it doesn't really change a lot.
"If you actually believe you can win the tournament, then you're focused on yourself and not actually the field." He says almost off-handedly: "I feel like, yeah, if things click here, yeah, I should be able to win the tournament here."
Federer was hampered by a bad back at Wimbledon 2013 and this may have caused the spectre of doubt to lay its cold hand on his confidence. He certainly has faith now in his game and his physical strength.
"This year I feel all the options are there. Return, serve, serve and volley, come in, my backhand, everything is working to my liking. For that reason, I feel I'm a bit more relaxed mentally because I know it is there," he says. His path to the business end of the tournament does not look the most arduous. His likely opponents successively will be Paulo Lorenzi, Julien Benneteau, Marcel Granollers, Jerzy Janowicz and compatriot Stanislas Wawrinka.
These players would once have been mere stepping stones for Federer on the road to another triumph. Now, though, there is the suspicion big hitters such as Janowicz can unnerve him.
Federer, though, has won on grass at Halle, has targeted Wimbledon as his best hope of adding to his Grand-Slam haul and has been working on his fitness to withstand the rigours of what he hopes will be two weeks of competition on grass.
"I'm totally at peace," he says in a sentiment that is worthy of a spiritual Sunday. It is made on a Saturday in advance of today's champion's press conference from a certain Scot.
Let there be no mistake, however. Federer still has faith it is his time.