"silent day" is correct and usable in written English.
In this context, you would use it to convey the idea of a day without sound or noise. For example, "every Sunday, my family has a silent day when we refrain from speaking and try to listen for the small things in life."
The programme consists of 8 weekly 2.5-hour sessions, a silent day between session six and seven and home practice assignments of about 45 minutes, 6 days per week.
The largely Hindu Indonesian island celebrates Nyepi – Silent Day – by completely shutting down for 24 hours.
Silent Day follows on from raucous New Year's Eve celebrations, held to chase away malevolent forces.
Web radio's silent protest Internet radio stations are holding a silent day of protest today - complete with their own purpose-built logo - in protest at a proposal by the US government to hike up royalty payments to rights holders.
Through the characters of women, migrants, prostitutes, the illiterate, the imprisoned, madmen and seers, he charts extreme states of powerlessness and invisibility, entrapment and rebellion, or, as he writes in his fictional meditation on ageing, Silent Day in Tangier (1990), of solitude "so absolute the self dissolves".
This Festival is conducted once a year in conjunction with Nyepi or Silent Day.
Militant mortar fire, which had been intense in previous days, fell silent Wednesday, with commanders saying only a few militant snipers remained in the city.
North Korea remained silent Monday about the forthcoming summit with Donald Trump - three whole days after the White House made the shock announcement that the president would personally meet with Kim Jong Un.
Mr. Gandhi, as is his wont, remained publicly silent Sunday.
The league held its first Silent Sunday that October.
After the tumult of Thursday, the N.F.L. went mostly silent Friday.
