Why do people with ADHD sometimes arrive way too early and other times horribly late 

People with ADHD often describe a confusing relationship with time. They may arrive excessively early one day and surprisingly late the next. According to NHS guidance on ADHD, this inconsistency is not about motivation but about how ADHD affects the brain’s executive functions, which help with planning, organisation and time estimation. 

The science behind ADHD and time perception 

NICE guidance NG87 explains that difficulties with organisation, time management and prioritisation are recognised as common challenges in ADHD. These stem from differences in executive function, which makes it harder to plan ahead or switch tasks on time. Many people also experience what clinicians call time blindness – a reduced awareness of the passing of time that can cause them to misjudge how long things take or lose track of the clock entirely. 

Executive function and time blindness 

Research from the Mayo Clinic notes that adults with ADHD often underestimate how long tasks take, miss transitions and find it difficult to move between activities. Neurological studies suggest that differences in dopamine signalling, which influences focus and motivation, may make it harder to sustain effort on tasks that do not provide immediate rewards. These combined effects on time perception and attention can explain why people with ADHD may sometimes be impulsively early and at other times unexpectedly late. 

What helps improve punctuality 

According to NICE guidance, structured routines, external reminders and time-management training can make a real difference. Using visual timers, phone alarms or digital planners helps externalise time so it becomes more tangible. Medication and structured psychological support, such as CBT-based coaching, can also help people apply these tools more consistently. Private clinical services such as ADHD Certify provide assessments and medication reviews for adults and children who need structured diagnostic support in line with UK NICE standards. 

Key takeaway 

Punctuality challenges in ADHD are not a sign of laziness. They reflect genuine neurological differences in how time and motivation are processed. With the right combination of structure, clinical support and self-understanding, it is possible to feel more in control of time and reduce the stress of always being either too early or too late. 

Harriet Winslow, BSc

Author

Harriet Winslow is a clinical psychologist with a Bachelor’s in Clinical Psychology and extensive experience in behaviour therapy and developmental disorders. She has worked with children and adolescents with ADHD, autism spectrum disorder (ASD), learning disabilities, and behavioural challenges, providing individual and group therapy using evidence-based approaches such as CBT and DBT. Dr. Winslow has developed and implemented personalised treatment plans, conducted formal and informal assessments, and delivered crisis intervention for clients in need of urgent mental health care. Her expertise spans assessment, treatment planning, and behavioural intervention for both neurodevelopmental and mental health conditions.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the author's privacy.

Dr. Rebecca Fernandez, MBBS

Reviewer

Dr. Rebecca Fernandez is a UK-trained physician with an MBBS and experience in general surgery, cardiology, internal medicine, gynecology, intensive care, and emergency medicine. She has managed critically ill patients, stabilised acute trauma cases, and provided comprehensive inpatient and outpatient care. In psychiatry, Dr. Fernandez has worked with psychotic, mood, anxiety, and substance use disorders, applying evidence-based approaches such as CBT, ACT, and mindfulness-based therapies. Her skills span patient assessment, treatment planning, and the integration of digital health solutions to support mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the reviewer's privacy.