Federer will kickstart his claycourt campaign at next month's Geneva Open.
The claycourt Grand Slam, which was postponed by four months last year and took place in front of limited crowds, will finish on June 13, two weeks before the expected start of Wimbledon.
Swiatek breezed past second seed Belinda Bencic 6-2, 6-2 in the final.
The 19-year-old became the first Polish player to win a Grand Slam singles title when she beat Sofia Kenin in the French Open final.
Nadal crushed Djokovic to clinch a record-extending 13th French Open title and draw level with Federer for the most number of Grand Slam singles titles by a male.
The Spaniard won a record-extending 13th French Open title and tied with Swiss Roger Federer's tally of 20 Grand Slams.
Swiatek became the first Polish player to win a Grand Slam singles title when she beat American fourth seed Sofia Kenin 6-4, 6-1.
While Djokovic, who had lost five of his nine previous French Open semi-finals, was given a fright it always looked as though his vast experience would prove decisive.
Nadal moved within one win of a record-equalling 20th Grand Slam title by reaching the French Open final with a comfortable 6-3, 6-3, 7-6(0) victory.
Swiatek became the youngest player to reach the French Open women's final in 19 years when she crushed Argentine qualifier Nadia Podoroska 6-2, 6-1.