How long have the children been gone in A Wrinkle Time?

In Madeleine L'Engle's novel "A Wrinkle in Time," it's never explicitly stated how long Meg, Charles Wallace, and Calvin have been gone. However, we can glean some information from the text:

* The trip is described as taking a long time: Meg experiences time differently on Camazotz, which makes it hard to gauge how long they've been gone. The text does mention that Mrs. Whatsit tells them, "We have traveled far, and it is a long way back," implying the journey was lengthy.

* Meg's father has been searching for them: While searching for his children, Mr. Murry mentions that "a month had passed" and people were beginning to worry. However, this isn't definitive as he may be exaggerating to emphasize the urgency of the situation.

Ultimately, the length of their absence is left somewhat ambiguous to focus on the emotional and psychological impact of their journey rather than the precise duration of their time away.