I’d gently suggest Dan 10:1-3 does not describe a fast. Rather, Daniel mourned for 3 weeks, and deprived himself of "rich/choice/tasty" foods. Bread or other "plain" foods are not suggested, and clearly, eating bread is not fasting. Daniel also used no lotions during these 3 weeks (vs 3), which has nothing to do with a fast.

The Day of Atonement does describe fasting for 24 hours. This is representative of other biblical fasts, which use the day as the unit for fast duration: Jer 36:6, I Sam 31:13, I Chron 10:12, Ester 4:16, Ex 34:28-29, I Kings 19:8, Isa 58:3-5, 1 Sam 7:6. Fasts are then described in Judges 20:26, 2 Sam 1:12 etc. as lasting until evening. Therefore, while a minimum time for fasting is not stated in the Bible, non-“emergency situation” fasts of less than a day are neither described nor indicated.

The “afflicting of our souls” is also a described part of fasting (e.g., Isa. 58:3). Matt 6:16-18 then describes a “sad countenance” and “disfigured faces” as inappropriate ways to “advertise” our affliction. These descriptions are logically of missing more than one meal. Skipping a meal to pray and study is very commendable, but is not a biblical fast. :-)