Challenges faced and how I overcame them

I think I am not very good at estimating how long a task will take me to finish. I recollect an instance during my tenure at Cognizant when I was working with a client from the UK. My task was to transform the services that belonged to our client. To consume these services consumers possessed valid certificates and each of these certificates had a specific issuer. It was during this time when the issuers of these certificates were changing, and we had to renew the certificates. In a process to impress my client, I committed to complete the entire task within one day. At that time, I thought that it was achievable, but it ended up taking three days and my client was not happy. Looking back, I realize that I should have been more conservative with my estimate to the client. I realized that a client won’t be disappointed if I am clear about the timeline in advance, but they are going to be upset if I promise to deliver something and then I fail. Since then I have improved significantly, and it has always not only helped me with my problem of underestimating time but also in being punctual.