Today you might have noticed an error in some mobile apps with content tied to the liturgical calendar in the United States. Like most countries, we have our anomalies at times. Today is a good example as we celebrate the optional memorial of St. Jane de Chantal, religious. Check out this link to get the complete saga of this feast day’s movement throughout the liturgical calendar in the US and elsewhere. It really is today in the Ordinary form of Roman Rite liturgies all over the world.
I see that my usually trusty iMissal app still holds a place mark for this memorial on August 18 this year [again, it is a long story outlined in the linked site by Fr. Z] . But a cursory look at other apps reveal they’re up to the mark with the 2001 universal date change : iBreviary, Divine Office, Universalis. So far so good. Remember: apps, like people, are not perfect. Check your reliable sources if you really need accuracy.