Another meaning of через is “in” in the sense of “time period at the end of which something will happen.” In this sense it also takes the accusative case.
| Добыча нефти начнётся через два дня. (adapted from this source) |
Petroleum extraction will begin in two days. |
| Через месяц женюсь! |
I'm getting married in a month! |
| Отель "Марко Поло" в Москве откроется через год. (source) |
The Marco Polo Hotel will open in Moscow in a year. |
| Через неделю будет устный экзамен. |
There will be an oral exam in a week. |
This use of the word can also happen in the past tense, in which case it is best translated “later”:
| Сначала в Москву прилетел я, а через два дня прилетела и моя сестра. |
First I came to Moscow, and two days later my sister also came. |
| Британские колонии в Северной Америке объявили независимость в 1776-ом году, а через тринадцать лет состоялась революция во Франции. |
The British colonies in North American declared independence in 1776, and thirteen years later a revolution took place in France. |