Q: Is there a limit to the number of times a parish can have the Eucharistic benediction in a day.

A:  Yes. Twice.

According to the instruction Eucharistiæ saramentum (Congregation for Divine Worship, 1973), “Where there cannot be uninterrupted exposition because there is not a sufficient number of worshipers, it is permissible to replace the blessed sacrament in the tabernacle at fixed hours that are announced ahead of time. But this may not be done more than twice a day, for example, at midday and at night.”