The card does not name the time of day. The manufacturer writes that the salt invigorates wonderfully and lifts the mood; baths are taken, according to it, as a course of 10–15 procedures every day or every other day for 10–20 minutes. The card gives no confirmation of an invigorating effect.
General information (not a manufacturer's instruction): if the salt invigorates you, it is better not to take the bath just before going to sleep.