MARCELLUS It faded on the crowing of the cock.
Some say that ever ’gainst that season comes
Wherein our Saviour’s birth is celebrated
This bird of dawning singeth all night long,
And then, they say, no spirit dare stir abroad,
The nights are wholesome, then no planets strike,
No fairy takes, nor witch hath power to charm,
So hallowed and so gracious is that time.
HORATIO So have I heard and do in part believe it. (1.1.156-164)
Marcellus confirms: it faded on the crowing of the cock; yes, that’s exactly when the Ghost disappeared. (Faded is good: of course the Ghost didn’t fade, it walked offstage or down through the trap, but Marcellus overwrites that in the memories of the audience.)
He continues, though: some say that ever ’gainst that season comes wherein our Saviour’s birth is celebrated—that is, just before Christmas—this bird of dawning singeth all night long. What? Roosters crow all night in Advent? Really? And then, they say, no spirit dare stir abroad, the nights are wholesome, then no planets strike, no fairy takes, nor witch hath power to charm, so hallowed and so gracious is that time. Marcellus has heard that evil spirits cannot act at that time, that for those weeks the world is safe from malign influences. What’s going on? Why’s he adding this? Partly it’s an eagerness to add something: it’s not just the scholar, the academic who knows things about ghosts; he’s contributing, and keen to be seen as knowledgeable, not ‘just’ a soldier on guard. It comes across as credulous, though—and perhaps suggests that in fact now is not that time; although it’s cold, it’s probably not being suggested that it’s currently approaching Christmas (although some have argued that, and it’s probably defensible?) and there has definitely been an unquiet spirit walking. If it is to be imagined as December, then the ghost is evidence that the state of things is confused, disordered; if it’s not, then it suggests that these are dangerous times indeed, without particular divine protection: the ghost shouldn’t be able to be there, and yet it is.
Horatio confirms, quite kindly; he’s not going to dismiss Marcellus or mock his more popular, folkloric contribution: so have I heard and do in part believe it. Yes. (And, dramaturgically, this little exchange gives just a little bit more time at the end of the scene for the actors to ready themselves backstage, because—peeking ahead—the following scene has a large ensemble entering in procession and, not impossibly, the Ghost needs to double one of the characters involved and so needs time to remove helmet etc.)