How would I go about in writing a conditional statement that checks if current post's post date is from this year?
You mean a Conditional HTML or a query filter in a view?
In any case you would have to compare as NUMBERs, since Toolset saves timestamps, you cannot compare by a date but only by another timestamp, which are numbers.
Conditional HTML is explained here: https://toolset.com/documentation/user-guides/conditional-html-output-in-views/, https://toolset.com/documentation/user-guides/conditional-html-output-in-views/checking-types-fields-and-custom-fields/#using-fields-together-with-date-filters
You can use these constants as well:
https://toolset.com/documentation/user-guides/date-filters/
This should help to craft such conditions, however please do not hesitate to ask me if something is not clear.
I am referring to conditional html. What I want to do is basing on the the post date if it's within the past three months, it will display a message.
I have looked through the docs and came up with the following.
[wpv-conditional if="( '[wpv-post-date]' gt 'PAST_MONTH(3)' )"]posted within the past three months[/wpv-conditional]
