How to style by date monthly ranges QGIS?
I do not suggest using the date functions, because the distance from e.g. 2019-10-28 to 2019-11-1 would be 0 where you expect 1. Instead access the year and month via substr function and calculate the distance in months say from 10/2019 onwords. The following Expression does the trick:
(to_int(substr("my_date", 0, 4)) - 2019) * 12 + (to_int(substr("my_date", 6, 2)) - 10)
For testing purposes I created a dataset and a virtual field as follows:
result:
Then I use a categorized renderer like this:
resulting in
this expression calculates the difference in months from now on and a date in the future
if(
year(now()) = year("my_date"),
month("my_date") - month(now()),
month("my_date") - month(now()) + (12 * (year("my_date") - year(now())))
)
To style you can use a rule-based style using 6 rules:
- current month:
if(year(now()) = year("my_date"), month("my_date") - month(now()), month("my_date") - month(now()) + (12 * (year("my_date") - year(now())))) = 0 - next month:
if(year(now()) = year("my_date"), month("my_date") - month(now()), month("my_date") - month(now()) + (12 * (year("my_date") - year(now())))) = 1 - second next month:
if(year(now()) = year("my_date"), month("my_date") - month(now()), month("my_date") - month(now()) + (12 * (year("my_date") - year(now())))) = 2 - third next month:
if(year(now()) = year("my_date"), month("my_date") - month(now()), month("my_date") - month(now()) + (12 * (year("my_date") - year(now())))) = 3 - forth next month:
if(year(now()) = year("my_date"), month("my_date") - month(now()), month("my_date") - month(now()) + (12 * (year("my_date") - year(now())))) = 4 - fifth next month:
if(year(now()) = year("my_date"), month("my_date") - month(now()), month("my_date") - month(now()) + (12 * (year("my_date") - year(now())))) = 5 - beyond 5 months:
if(year(now()) = year("my_date"), month("my_date") - month(now()), month("my_date") - month(now()) + (12 * (year("my_date") - year(now())))) > 5