sola said:
warm hello siblings

. how can we identify our chart ruler without knowing birth time?
I'm no adept at astrology, but I don't think not knowing your birth time will make a drastic difference in the actual astrological position. It's well within a day and you can try various sites and experiment with a specific time and see what planet comes up the most out of all those different sites.
Whichever planet comes up the most is likely the most accurate reading of what your chart ruler is. You can then take a look through
here of all the planets and read up on their rulerships, what they symbolize, etc. If you find you really personally identify with the planet at a core level, what it represents, etc, then it's likely to be your chart ruler.
For example, Mars is the planet of war. Battle, fighting, aggression, fire, weapons, sharp cutlery, steel, violence. Someone with Mars as their chart ruler is likely an individual who caters to aggressive means, enjoys fighting, combat, battle, may enjoy a job/career in the military or being a surgeon, working in some way with fire, knives, sharp tools, explosions or extremes of forcefulness like boxing, wrestling or extreme body building/exercising. Generally the keywords to this chart ruler are fire, sharp and force.
You can use that as a guideline to read up on other planets and figure out their own caterings and if it fits with you strongly as a chart ruler to narrow down accuracy.