
    Write a function that converts patient admission timestamps from the hospital's internal yyyy-mm-dd format to the standard dd-mm-yyyy format used in medical reports and patient documentation. The standardized date conversion is essential for maintaining consistent emergency room visit records and accurate patient influx analysis across all hospital departments.
    

    
import re

def change_date_format(dt):
    """
    Write a function that converts patient admission timestamps from the hospital's internal yyyy-mm-dd format to the standard dd-mm-yyyy format used in medical reports and patient documentation. The standardized date conversion is essential for maintaining consistent emergency room visit records and accurate patient influx analysis across all hospital departments.
    

    """
import re

def change_date_format(dt):
    """
    Write a function that converts patient admission timestamps from the hospital's internal yyyy-mm-dd format to the standard dd-mm-yyyy format used in medical reports and patient documentation. The standardized date conversion is essential for maintaining consistent emergency room visit records and accurate patient influx analysis across all hospital departments.
    

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