vacmurse lujvo

m1=c1 is the dusk of day m2=c2 at location m3=c3.

Cf. cermurse.

In notes:

murse
x1 is the [astronomical] twilight/dawn/dusk/half-light/glimmering of day x2 at location x3.
cermurse
m1=c1 is the dawn of day m2=c2 at location m3=c3.