Those of us who are old enough to remember the 'brick' phones of days gone by will recall that those handsets could last for weeks without needing to be recharged; and while we may be looking back through rose-tinted spectacles to some extent, it’s certainly the case that your modern smartphone will rarely last as long as you’ll want it to.
Most phones these days will last for a day of use, and in some cases possibly two, but the days of your handset lasting for a week between charging sessions is long gone. However, there are some things you can do to keep it running for longer, so that you're not reaching for the charger quite so often.