Nice! Back in the day, 'daylight' in the UK was 4300k. What we now know as daylight was then called 'Tropical daylight'. At some point, 4300k was renamed cool white (tho I remember Sylvania used to call it UK Daylight for a while). I'm surprised to see this in a Philips tube made this late tho....

as mentioned "Daylight" marked cool white tubes are specifically a British thing, these tubes are specifically made for the UK or one of our territories, notice also how its specifically marked in British type nomenclature "MCFE" rather than "TL", but as above strange to see it on a tube so late! by the mid 1970's most tubes where marked cool white instead, although it is worth noting that there is a difference between "cool white" and Colour 33/British Dayalight, cool white tubes are often 4000K-4200K where as Colour 33/British daylight should always be 4300K, guess no one bothered telling the french factory the terms had changed! some very nice tubes tho regardless of that, you know they would go on for yonks