You can make the changes in the travel date/time.
Below are the steps to make the changes in the travel date through udChalo profile.
Step 1: Login into your profile through your registered email id or phone number with udChalo.
Step 2: Once you are login go to your profile select My Booking option. 
Step 3: Select the flight for which you want to make the changes in the Upcoming flight column.
Step 4: Once you select the flight for which you want to make the changes, then select Reschedule option in the bottom of the page. 
Step 5: In the next step you have to select the New Travel Date and click on Reschedule.
Step 6: In the next page, you will receive different flight options. Select convenient flight and click on Book now.
Step 7: In the next page you will get the details of your new flight and fare breakup. Check the details and click on "Book Now"
Step 8: You will receive the new ticket copy on your Email ID and confirmation on your phone number