x1 is the date [day,{week},{month},year] of event/state x2, at location x3, by calendar x4.
(time units in x1 are specified as numbers separated by pi'e or are unit values massified with joi); (cf. cmavo list de'i, djedi, jeftu, masti, nanca, tcika)
The date [day,week,month,year] x1=d1=k1 is recurrence/repetition of the date [day,week,month,year] of the first event x2=d2, for the x3=k3'rd time, in system x4.