There's no hard and fast rule about what time of day is best for which frequencies/bands. Listen carefully and often. Generally, lower frequencies are better received after local sundown, at which time higher frequencies may not be active. It depends on the sunspot number, time of year, and many other factors.
Frequency and wavelength are inversely proportional: higher frequency = shorter wavelength. For example, the ten meter amateur band is at 28 - 29.7 MHz. Twenty meters is 14 - 14.35 MHz. 80 Meters is 3.5 - 4 MHz. Notice that as wavelength (what you're calling "mitter band") increases, the corresponding frequency or band of frequencies decreases.