For both the Celtic and German tribes at the time of Tacitus considered the Moon auspicious when in its different phases:
“The community gathers, if nothing unusual or sudden happens, at certain times when the moon is new or full, because they consider this the luckiest beginning to discuss matters. Also, they do not calculate the number of days, but the number of nights. In this way they state purpose and commitment. Night does precede the day.” – (Chapter 11) Tacitus , 98 CE.