leap year birthdate

I have a tcl that calculates age for one of our systems. One of the tests is to find out whether the person has had a birthday yet this year. I am converting the birthday to julian dates and subtracting. I found an interesting problem today…. The tcl has a problem with converting the birthday 2/29 to a julian date in a non-leap year. I am enclosing the portion of code that is not working in hopes that someone has a suggestion!

When the brday came out to 2/29, I get a Tcl callout error {unable to convert date-time string “2/29”}

#### Get four digit year of birth, month and day, omitting leading zeros

set byear [string range $dob 0 3]

if {[string range $dob 4 4] == “0”} {

set bmonth [string range $dob 5 5]

} else {set bmonth [string range $dob 4 5]}

if {[string range $dob 6 6] == “0”} {

set bday [string range $dob 7 7]

} else {set bday [string range $dob 6 7]}

set brday $bmonth/$bday

set rbjday [clock format [clock scan $brday] -format %j]

set bjday [string trimleft $rbjday 0]

#### Have they had a birthday yet this year?

set ageDays [expr $day – $bday]

set ageMonths [expr $month – $bmonth]

set ageYears [expr $year – $byear]

if {$ageDays < 0} {set ageMonths [expr $ageMonths - 1]} if {$ageMonths < 0} {set ageYears [expr $ageYears - 1]} Thanks! Kathy