Why do both of my apps give me different ovulation times?

Jill

I have <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a>. by Glow and the <a href="https://play.google.com/store/apps/details?id=com.glow.android">Glow app</a>. I entered in the same cycle information, but my fertile windows and ovulation days are different for each app.

Does anyone else notice this?

I’m not sure which is most accurate.