Annual boiler services and contract maintenance visits have a habit of quietly becoming eighteen-month gaps instead.
Recurring work - annual services, contract maintenance, regular site visits - has a specific failure mode: everyone means to book the next one, nobody actually does, and an annual service quietly becomes an eighteen-month one, usually noticed only when the customer asks why nobody's been in touch.
Why recurring work is easy to lose track of
One-off jobs have an obvious end point that prompts the next action. Recurring work doesn't - there's no natural trigger to book the next visit unless something is actively tracking when it's due.
Letting the schedule do the remembering
Setting a recurring frequency once - weekly through to annual - means the next visit gets scheduled automatically, without anyone needing to remember a date eleven months in the future. Recurring jobs turn a manual memory task into a background process that just quietly keeps happening.
The verdict
Nobody forgets an annual service on purpose. They just don't have a system reminding them of a date nearly a year away - until they do.