The need to adapt to environmental changes has necessitated biological timing in all organisms. Understanding these rhythms underpins the diagnosis and treatment of many endocrine conditions. We have therefore dedicated the winter issue of The Endocrinologist to ‘timing in endocrinology’.

In this issue, we have gathered articles from a wide range of expert contributors. Sasha Howard describes why the timing of puberty is changing and why it matters. Thomas Upton outlines the importance of glucocorticoid pulsatility. Kugajeevan Vigneswaran and Sesh Kamal Sunkara examine some of the time-related concepts in reproductive medicine and consider the challenges faced by healthcare professionals working in the field of infertility. David Ray highlights the need to embrace the biology of the circadian clock to enhance diagnostics and therapeutics for widespread human benefit.

Aimee Di Marco and Fausto Palazzo discuss the optimal timing of parathyroid surgery in preganancy. Louise Hunter writes about circadian misalignment and metabolic health. Finally, Anneke Graf reminds us that the pulsatile nature and rhythmic pattern of hormone secretion can have important implications for ordering and interpreting endocrine investigations.

It has been a pleasure for me to work with a great team at the Society for Endocrinology as the Editor of The Endocrinologist. As I approach the end of my term, I am delighted to hand over to Helen Simpson, who has already been making an important contribution to the magazine as Associate Editor.

With warmest wishes and season’s greetings

Amir Sam