This is quite a difficult question to answer because there are so many different variables and parameters involved. It is true to say that one man's meat is another man's poison. Both working patterns have their merits and pitfalls. In over four decades as a taxi driver I have worked pretty much every type of shift you can possibly imagine, including some very weird ones during lockdown.
From a traffic perspective, working during the day can be absolutely horrendous. It can be extremely challenging, highly stressful and quite damaging to a driver's mental health. There is generally less street hailing during the day, therefore more time is spent ranking up. Using one or more of the apps available to the industry can help alleviate any gaps between street jobs. You can boost your income quite rapidly if the apps are used in the right way, this means marrying up pre-bookings as well as doing immediate app jobs. Of course this needs to be tempered by the fact that you can't move anywhere particularly quickly.
One advantage to working during the day is that it is easier to deal with breakdowns and running repairs. Generally garages are open and breakdown services such as the AA and RAC seem to move that little bit quicker to assist you. Accessing services such as food and drink establishments, as well as toilets, is also significantly easier.
Working during the day does generally mean you end up working longer hours than if you were working at night. However, it does give you the opportunity of spending more quality time with family and friends.
Despite having worked during the day for a period of time, the majority of my four decades in the saddle as a cabbie has been at night. Working during the small hours is a very different prospect to the daytime. When
I first started nights there was a camaraderie which was second to none. Although that has diminished considerably, it is still there in some small part and can be quite useful in breaking up the evening. It is widely recognised that night work is more lucrative too, primarily because you are working off of tariffs two and three. This therefore can potentially reduce your working hours considerably. There is significantly more street and rank work at night but many drivers prefer to work the apps late at night. This is in part due to the fact that it is considered safer than doing street work - you have a record of who is getting into your taxi.
Generally manoeuvring around London is significantly easier at night although this can be baulked when entering areas such as Soho or Covent Garden - then all bets are off. The clientele is also somewhat different, with alcohol playing a major factor in any customer's demeanour at night. The prospect of somebody vomiting in your taxi can be a very real problem. Night work generally carries the same dangers from the public as any other industry when the sun goes down.
The good and the bad
Access to services is also problematic with toilets almost non-existent, eateries are available but the later it gets the more sparse they become. As for finding a garage or accessing a breakdown service, again you might have problems as the nighttime progresses.
From a family and social perspective, unless you can commit to at least one or two days off a week, your personal life can start to suffer. The reason for this is because you are simply not there or awake when family or friends are. Also, your sleep patterns are quite frankly shot to pieces. You just don't sleep well. All that said, the money can be good and you do commit to shorter hours.
Ultimately, whatever times you decide to work, always make sure that you take a break and make time for yourself and the family. Working all hours won't necessarily make you happy, but it will certainly make you the wealthiest corpse in the graveyard.