One of the challenges for every writer is to convey a sense of time to the reader.
The passing of time is a perception; it can appear to go fast or slow. Achieving that in your writing is an art!
Here though, I want to focus on the actual time: the time of day, the time of year, the era even. Knowing when things happen provides a context within which your story sits, and absorbing this information should enrich the reader’s experience.
Aiming to show rather than tell, a short cut like ‘It was the nineteenth of September in the year 1901.’ is not recommended. Instead, refer to what your character witnesses: something that illustrates it’s mid September in the early 1900s.
Avoid being too specific – unless the precise time is essential to the plot. Instead, give a sense of the time of day, using what the character sees.
Use what the character hears: the dawn chorus, a clock alarm, the hooting of an owl.
Time of day might also be indicated by scheduled events: meals, or going to or returning from work.
Depending on the location for your story, seasonal changes are usually well understood. My Safari Supper novel is set in a small seaside town, not unlike Salcombe in south Devon, so I can benefit from what I know of local conditions.
If your story is set in Australia, for example, there will be different seaonal changes.
Things that are constant are not so helpful in giving a feel for a time of year. In Salcombe that would be the wind, and the sound of sea gulls.
Festivals clearly indicate a time of year – without the writer having to spell it out.
If a writer mentions a world event – a war, the death of a famous person, a natural disaster – the majority of readers will be able to recall the circumstances and understand the historical context of the story.
Artefacts can also indicate era. Basic domestic arrangements – like the provision of electric lighting, or siting of WCs indoors – can give a sense of an era. Be sure to research carefully!