The phrase "a day when public" is not complete and lacks context, but it is grammatically correct and usable in written English.
You can use it when referring to a specific day that is significant for public events or actions, but it needs to be followed by additional information to clarify its meaning.
Example: "It was a day when public opinion shifted dramatically in favor of environmental policies."
Alternatives: "a day of public significance" or "a day for public action".
In a day when public lands around the country are being drilled, chopped and drained, these oases become even more treasured.
Every day students spend out of class is a day when public buildings go unused and parents have to restructure their lives.
The one to watch: In a day when public sculpture veers between soulless and kitsch, young Scot Michael Vissocchi, winner of the last Jerwood sculpture prize, offers a new monumental voice.
The disclosure of its purchase – for £20,000 – came during a day when public argument for and against the £9bn new runway, expected to be given the go-ahead by the Government perhaps as early as this week, reached new heights of antagonism.
He said the relaxation of the rules "extends a pattern of disowning and diminishing the teacher quality provisions in the law, and postpones the day when public education will realize its goal of equal opportunity for all".
As the court said, in one of its other decisions of that day: "When public evils ensue from individual misfortunes or needs, the legislature may strike at the evil at its source".
By Jonathan Schell The New Yorker, March 24 , 1975P. 31 Several years ago, around the time of the first Earth Day, when public concern over the state of the natural environment was becoming a political issue on a national scale, one of the TV news programs began a series of reports entitled "Can This World Be Saved?"... Before long, the series was dropped.
In some cities, marriages can be celebrated on Sundays (the day when public offices are closed), while, in others, spouses can only choose from the other days of the week.7 Therefore, the results that are associated with Sunday must be read in the light of these dispositions.
The attorney general made his remarks on an otherwise quiet Sunday, a day when the public and law enforcement agencies were on the highest possible alert for additional terrorist attacks here and against American interests around the world.
Faced with a series of demonstrations – fishermen and stockbreeders will join blockades on Thursday when public and private sector workers also take to the streets – analysts say any honeymoon period Tsipras may once have enjoyed is over.
Every day that we fail to resolve this to our satisfaction … is a day when our credibility in the public eye is likely to diminish".
