time format problem

[bbvic]

hi.
i have a question about time format.
first of all, my code reads an original text file.
after calculate time, it writes to another text file which name is write.txt

this is the result of write.txt
====================
2200,321,11:35,23:55
2201,326,12:50,24:15
2209,328,10:00,25:05
2203,325,11:00,25:05
2205,322,10:00,25:05
2206,307,9:30,25:05 (don't know why i got 9:30, not 09:30)
2207,323,10:00,25:05
2189,310,13:25,23:50
2197,318,13:15,23:45
2202,327,11:30,23:50
2204,324,10:30,25:05
=========
this is time calculation part.
###########################Start Up calculation####################################

set startUp $arrayHs4($k) ;# $before values from getvalue before$houseNumber before
set splitStartTime [split $arrayHs5($k) :]
set startTimeHourIndex [lindex $splitStartTime 0]
scan $startTimeHourIndex %d startTimeHourIndex
set startTimeHour [format "%02i" $startTimeHourIndex]
scan $startTimeHour %d startTimeHour

set startTimeMinIndex [lindex $splitStartTime 1]
scan $startTimeMinIndex %d startTimeMinIndex
set startTimeMin [format "%02i" $startTimeMinIndex]
scan $startTimeMin %d startTimeMin
# first movie - startUp minute
set calMin [expr $startTimeMin - $startUp]

if {$calMin >= 0} {
set occupiedTimeMin "$calMin"
scan $occupiedTimeMin %d occupiedTimeMin

if {$occupiedTimeMin <10} {

set occupiedTimeMin [format "%02i" $occupiedTimeMin]
scan $occupiedTimeMin %d occupiedTimeMin

#set occupiedTimeReg "$startTimeHour:$occupiedTimeMin"
set occupiedTimeReg [format "%02i:%02i" $startTimeHour $occupiedTimeMin]

}
set occupiedTimeReg [format "%02i:%02i" $startTimeHour $occupiedTimeMin]

} else {
set occupiedTimeHour [expr $startTimeHour - 1]
set occupiedTimeMin "[expr $calMin + 60]"
scan $occupiedTimeMin %d occupiedTimeMin
if {$occupiedTimeMin <10} {
#set occupiedTimeMin "0$occupiedTimeMin" ;# Time (min) format
set occupiedTimeMin [format "%02i" $occupiedTimeMin]
scan $occupiedTimeMin %d occupiedTimeMin
set occupiedTimeReg [format "%02i:%02i" $occupiedTimeHour $occupiedTimeMin]

}
set occupiedTimeReg "$occupiedTimeHour:$occupiedTimeMin"
set occupiedTimeReg [format "%02i:%02i" $occupiedTimeHour $occupiedTimeMin]

}
----------------

would you please help me why i got 9:30 instead of 09:30?

Thank you in advance.