Mine last up to 4 days then it dropped down to 1 day in less than one hour. (It depends on how much time you use your phone and which apps you are using. Also, the phone is monitoring battery usage in the background, calculating an estimate on how much days remain for the battery to die, updating the number of days and hours it takes for the battery to last which is displayed in device care as shown in the screenshots. Experiment you can try: You can increase the number of days and hours showed in device care by spending less to no time on your phone than usual and not charging it for several days.
After writing and posting the above comment the time decreased by 4 hours. My battery level is currently at 62% and remaining time decreased to 1 days 18 h while editing this comment and adding two more pictures.
What I want to say is, don't believe the time left for battery to die displayed in device care if you are an irregular user (Having an irregular pattern in using your phone everyday). It does not mean the battery will take exactly 1 day 18 hours to die in my case because I am an irregular user, I don't use same apps at for the same amount of time everyday). It can take more or less time depending on how you use your phone. The time is just a reference of how much time is left for the battery to die based on your phone usage. Trust the time displayed if you are a regular user (Similar pattern in apps usage everyday).