x1 (number) is the month notation of the date of event/state x2, in system x3.
masti zei detri. As default, the number x1 is counted from the first month of the year. See de'i'i for BAI. See also detke'u; masnpa, masnre, masnci, masnvo, masnmu, masnxa, masnze, masnbi, masnso, masndau, masnfei, masngai, masnjau, masnrei, masnxei, masnvai.