retrieving part of a string

If I have a string of something like this time stamp:

Is there a way to extract part of that string?
What I would like is the '-20' at the end which is the timezone (in quarters of an hour). Once I have just this part of the string I would then need to turn it into an integer.
Thanks for any help.

bool get_timezone(char* p, int& timezone) {
   p = strchr(p, '-');
   if (p == NULL || strlen(p) > 1)
      return false;
   timezone = atoi(p+1);
   return true;

void loop() {
   int timezone;
   if (get_timezone("12/02/09,12:20:00-20", timezone))
      Serial.println("no timezone!!!");

Thanks for the code mkwired!