(It all goes to Planck's constant.)
Well, it looks like we can measure distance. Not sure about this time, but since there is regular motion of planets around a sun, I suppose there is time. So there is units of distance/units of time.
Also, light comes from particles, which have fixed size. Light has frequency and wavelength. This is because it is a bit of energy from electrons jumping from orbit to orbit. To have frequency and wavelength you have to have speed.
Here is where I had to google: see the link
To find the photon energy in electronvolts, using the wavelength in micrometres, the equation is approximately
{\displaystyle E(eV)={\frac {1.2398}{\mathrm {\lambda } ({\mu }m)}}} E(eV)={\frac {1.2398}{{\mathrm {\lambda }}({\mu }m)}}
Therefore, the photon energy at 1 μm wavelength, the wavelength of near infrared radiation, is approximately 1.2398 eV.
Since {\displaystyle {\frac {c}{\lambda }}=f} {\frac {c}{\lambda }}=f, where f is frequency, the photon energy equation can be simplified to
{\displaystyle E=hf} E=hf
https://en.wikipedia.org/wiki/Photon_energy
