Exegesis:

en ekeinais tais hēmerais (cf. 1.9) ‘in those days’: a vague definition of time (cf. v. 17, where it is more definite).

meta tēn thlipsin ekeinēn ‘after that tribulation’: in the context, this refers to the thlipsis ‘tribulation’ in v. 19. The preposition meta ‘after’ in no way indicates the length of time intervening between the two events, whether great or small: it simply denotes the temporal succession of the events described.

The rest of the verse is patterned after the language of Isa. 13.10.

skotisthēsetai (only here in Mark) ‘shall be darkened’: the verb skotizō ‘to darken,’ ‘to lose (its) light’ appears only in the passive in the N.T.

to pheggos (only here in Mark) ‘the light,’ ‘the radiance.’

Translation:

In those days, as a general reference to time, is translated in some languages as ‘at that time,’ ‘then,’ or ‘then later.’

Tribulation, which is a noun of process, must often be translated as a verb, e.g. ‘after the people have suffered,’ ‘after they have had great troubles,’ or ‘after they have been greatly troubled.’

Will be darkened is in some languages equivalent to ‘will not shine’ or ‘will become dark.’

Give its light is usually translatable by some verb meaning ‘to shine,’ ‘to be brilliant,’ or ‘to glow.’ A literal rendering of ‘give light’ is often quite misleading.

Quoted with permission from Bratcher, Robert G. and Nida, Eugene A. A Handbook on the Gospel of Mark. (UBS Handbook Series). New York: UBS, 1961. For this and other handbooks for translators see here .