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.
x1=n1 is the birthday celebration with celebrators x2=s1 of x3=s2=j1, born to x4=j2 at time [birthday] x5=j3 and place x6=j4, with birthday party x7=s3.