Basic units of measurement for Time

[jordanbrauer]

Thanks @teunw for adding the basic time units via #35!

namespace UnitConverter\Unit\Time;

• Millisecond = ms
• Second = s
• Hour = hr
• Minute = min
• Day = day
• Month (31 days) = month
• Microsecond = μs
• Nanosecond = ns
• Week = week
• Year (365 days) = year

[teunw]

I think it might be better to make the month and year units calculatable.
So giving the years to convert from/to would give different results based on leap years for instance.

[jordanbrauer]

@teunw Great idea! How do you imagine the implementation of calculable months/years working?

I think we could make this work by implementing the ::calculate() class method on the Month and Year units (see Celsius & Fahrenheit units as an example).