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habits
Anchor the wake-up, not the bedtime
One small thing you could do
Pick the wake time you could hold seven days a week — honestly, not aspirationally — and set tomorrow's alarm to it. That's all. The bedtime takes care of itself once the anchor is in; your only job tomorrow is up-and-into-light, even if the couch and thirty open-eyed minutes is the whole performance.
Skip the bedtime rule and anchor the wake-up instead — every day, weekends too. Sleep needs differ body to body; fix one end and the other finds itself.