The Italian railway released schedules for many high-speed Frecce trains now bookable through December 2022. Some dates are exempt and the times vary, so check for your particular dates and times by searching on ItaliaRail.

Here are the cities and routes available:

Rome Termini to:

Bari
Bergamo
Bolzano
Fiumicino Airport
Genova
Lecce
Mantova
Milan (Milano Centrale)
Naples (Napoli Centrale)
Reggio Calabria
Trieste Centrale
Turin (Torino Porta Nuova)
Venice (Venezia Santa Lucia)

Florence (Firenze S.M.N.) to Napoli Centrale

Milan Centrale to:

Ancona
Bari
Battipaglia
Bolzano
Lecce
Naples (Napoli Centrale)
Pescara
Reggio Calabria
Roma Termini
Salerno
Sapri
Taranto
Trieste
Udine
Venice (Venezia Santa Lucia)

Naples (Napoli Centrale) to:

Bergamo
Bolzano
Brescia
Florence (Firenze S.M.N.)
Milano Centrale
Turin (Torino Porta Nuova)
Udine
Venice (Venezia Santa Lucia)

Venice (Venezia Santa Lucia) to:

Fiumicino Airport
Genova
Lecce
Milan (Milano Centrale)
Naples (Napoli Centrale)
Reggio Calabria
Roma Termini
Salerno
Turin (Torino Porta Nuova)

Fiumicino Airport to:

Roma Termini
Venice (Venezia Santa Lucia)

Bari to:

Rome Termini
Milano Centrale

Bolzano to:

Milano Centrale
Napoli Centrale
Rome Termini
Sibari
Genova P. Princ. to Roma Termini

Lecce to:

Milano Centrale
Rome Termini
Turin (Torino Porta Nuova)
Venice (Venezia Santa Lucia)

Reggio Calabria to:

Milano Centrale
Roma Termini
Turin (Torino Porta Nuova)
Venice (Venezia Santa Lucia)

Salerno to:

Milano Centrale
Turin (Torino Porta Nuova)
Venice (Venezia Santa Lucia)

Taranto to:

Milano Centrale
Turin (Torino Porta Nuova)

Turin to:

Lecce
Naples (Napoli Centrale)
Reggio Calabria
Rome Termini
Salerno
Trieste
Venice (Venezia Santa Lucia)

Trieste to:

Milano Centrale
Roma Termini
Turin (Torino Porta Nuova)

Udine to:

Naples (Napoli Centrale)
Milano Centrale

Other routes:

Battipaglia to Torino Porta Nuova
Bergamo to Roma Termini
Brescia to Napoli Centrale
Genova Porta Principe to Roma Termini
Genova Brignole to Venezia Santa Lucia
Mantova to Roma Termini
Pescara to Milano Centrale
Sibari to Bolzano