Why would a 21 year old girl who is flirting with me heavy disappear at the same exact time every night?

She made intentions clear but every day at 8pm EXACTLY she goes ghost. I haven’t asked about it yet. I know she has middle eastern parents and they can be strict but I can’t imagine her having a bedtime.
Why would a 21 year old girl who is flirting with me heavy disappear at the same exact time every night?
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