
    Develop a function for the bank's global fraud monitoring system that converts transaction dates from yyyy-mm-dd format to dd-mm-yyyy format to ensure standardized date representation across all international branches. The function must maintain the chronological accuracy of transaction timestamps while adapting to the bank's preferred date format for cross-border fraud analysis.
    

    
import re

def change_date_format(dt):
    """
    Develop a function for the bank's global fraud monitoring system that converts transaction dates from yyyy-mm-dd format to dd-mm-yyyy format to ensure standardized date representation across all international branches. The function must maintain the chronological accuracy of transaction timestamps while adapting to the bank's preferred date format for cross-border fraud analysis.
    

    """
import re

def change_date_format(dt):
    """
    Develop a function for the bank's global fraud monitoring system that converts transaction dates from yyyy-mm-dd format to dd-mm-yyyy format to ensure standardized date representation across all international branches. The function must maintain the chronological accuracy of transaction timestamps while adapting to the bank's preferred date format for cross-border fraud analysis.
    

    """
    return re.sub('(\\d{4})-(\\d{1,2})-(\\d{1,2})', '\\3-\\2-\\1', dt)