sedan dess betyder på engelska

ever since▼(continuously since a specified time or event)
adverb
[UK: ˈev.ə(r) sɪns] [US: ˈev.r̩ ˈsɪns]

since▼(from a specified time in the past)
adverb
[UK: sɪns] [US: ˈsɪns]

thenceforth▼(from that time on)
adverb
[UK: ˌðens.ˈfɔːθ] [US: ˌðens.ˈfɔːrθ]