I assume there is no indication on when and where the christening/baptism is taking place... Amalia's baptism took place within a month, while Liam's took over 4 months. It seems they prefer either Spring or Summer i.e., nice weather, so I wouldn't be surprised if Balthazar is baptized sometime next month or in May (depending on the location).
Amalia:
Born: 15 June 2014; Grand Duchess Charlotte Maternity Hospital in Luxembourg
Baptized: 12 July 2014; Chapelle de Saint-Ferréol in Lorgues
Liam:
Born: 28 November 2016; Beaulieu General Clinic in Geneva
Baptized: 7 April 2017; Chapel of the Choir, St. Peter's Basilica in Vatican City
Balthazar:
Born: 7 January 2024; Grand Duchess Charlotte Maternity Hospital in Luxembourg