The jetlag rule, in one line

You are shifting eight hours backwards, which is the easier direction because your body clock naturally runs slightly longer than 24 hours. The rule for westward travel: evening light is good, early morning light is bad. Expect four to six days to full adjustment, but most of the benefit lands in the first 48 hours if you get the light timing right.

Saturday 12 September — arrival

You land 14:40 with about five hours of useful daylight, which is close to ideal. Train to Bruxelles-Central takes 17 minutes and costs about €11, including the unavoidable airport supplement. Faster than a taxi in traffic and no negotiation required. Skip Uber: pickups are in the P1 garage on level 4 or 5, a few hundred metres' walk with bags.

Two instructions matter more than everything else: do not nap after 16:00, and do not go to bed before 21:30. If you are desperate, one 20-minute nap with an alarm, nothing longer. Then get outside and walk in daylight until dinner. Sunset is 20:04, so there is real light to use. Early dinner around 19:00, a proper meal. Stay up and keep the lights bright until 22:00. No caffeine after 15:00.

You will wake at 02:00–04:00. That is normal. Don't turn on bright lights and don't open your phone.

Sunday 13 September — the recovery day

Sleep in. No alarm before 08:30, and keep the curtains shut if you wake at 06:00, because early light drags your clock the wrong way. The Sablon antiques market runs Saturday and Sunday mornings and is the right kind of low-effort: outdoors, walkable, and it puts daylight on you. Big daylight exposure through the afternoon and again after 17:00. One nap allowed, 30 minutes maximum, finished by 15:30. Caffeine cut-off 14:00.

Monday 14 September — the event starts

You should feel roughly 70% normal. Now morning light is helpful rather than harmful, so get it. Full breakfast, coffee unrestricted before 14:00, and no naps at all. Push through the afternoon dip with a walk outdoors rather than more caffeine.