Consuming 6-8 dates daily starting 4 weeks prior to your due date has been shown to decrease the need for labor induction and augmentation (1) as well as to shorten the length of labor (2).
Specifically, in one study women who consumed dates prior to labor were in their first stage of labor (0-10 cm) an average of 8.5 hours compared to 15.1 hours for the non date eaters.
Though it is unclear why dates seem to have this effect, it is proposed that dates help to soften the cervix prior to labor which makes the process quicker.
In my own experience, upon admission to the hospital my cervix was fully effaced, the doctor who examined me was surprised and said it was “paper thin” despite being 1 cm dilated and not having any contractions.
Hours later my nurses thought I would be in active labor starting around midnight or 1 am, but it started at 9:45 when I went from 6 cm dilated at 9:30 to almost 9 cm by 10:45!
My baby was born three hours before the nurses predicted I would even start pushing.
I certainly don’t think dates are a magic pill, at the very least they don’t cause harm. If the small amount of evidence (both scientific and anecdotal) we have is true, they could shorten your labor. I think any woman who has experienced labor would agree a shorter labor is worth a few weeks of eating dates.