This calculator estimates jet lag recovery time using the relationship between time zones crossed, travel direction, and age. Eastward travel requires about 1 day per zone crossed; westward travel requires about 0.67 days per zone. Age multipliers adjust for biological differences: people under 30 recover faster (0.85x), ages 30-50 use the standard rate (1.0x), and those over 50 typically take longer (1.3x). These are population averages; individual recovery varies significantly based on sleep habits, light exposure, and personal resilience.
Your circadian rhythm (internal body clock) runs slightly longer than 24 hours. It's easier to extend your day by staying awake (westward) than to compress it (eastward), so westward adjustment is typically faster.
Take melatonin 2-3 hours before your desired local bedtime at your destination to help shift your internal clock forward (eastward travel). For westward travel, avoid evening light and melatonin. Always consult a healthcare provider before starting any supplement.
Yes—light exposure is the strongest reset signal. Seek morning light for eastward travel and evening light for westward travel. Adjust your sleep schedule days before travel, stay hydrated, exercise, and eat meals at local times to anchor your circadian rhythm.
Estimate only. Results reflect your inputs and standard formulas. Double-check important decisions independently.