set crontab {{* * * * /15 "set x 1"} {* * * * /2 "set x 2"}}

proc event:cron {} {
  global crontab
  set time [clock format [clock seconds] -format "%M %H %u %d %m"]
  proc check {time job} {
    scan $time "%d %d %d %d %d" t(M) t(H) t(u) t(d) t(m)
    set p(m) [lindex $job 0];set p(d) [lindex $job 1];set p(u) [lindex $job 2];set p(H) [lindex $job 3];set p(M) [lindex $job 4]
    set dojob 1
    foreach c {m d u H M} {
      if [string equal * $p($c)] {continue}
      if [string match /* $p($c)] {scan $p($c) "/%d" pattern; if [expr $t($c)%$pattern]==0 {continue} {set dojob 0; break}}
      set p($c) [split $p($c) ,]
      set match 0
      foreach pattern $p($c) {
        if [string match *-* $pattern] {
          set pattern [split $pattern -]
          set range ""; for {set x [lindex $pattern 0]} {$x<=[lindex $pattern 1]} {incr x} {lappend range $x}
          if [lsearch $range $t($c)]>=0 {set match 1; break}
          } {
          if $pattern==$t($c) {set match 1; break}
          }
        }
      if $match==1 {continue}
      set dojob 0; break
      }
    if $dojob==1 {logexec [lindex $job 5] 5 "Running cronjob \"[lindex $job 5]\""}
    }
  foreach job $crontab {check $time $job}
  }