What do you mean by annotation date, there is a declaration(announcement) date, ex-date, record date but I've never heard of an annotation date. Dividends are not decided always at the fiscal year end, in some countries they are approved by the shareholders general meeting which can happen at any time during the year, some companies pay quarterly, others annually, etc..
I don't think there is a systematic link between the declaration/ex date of dividends and the fiscal year, as the rules and payment period vary wildly from one country to another.
Some examples :
France, Germany, traditionally paid in April-May but this has been slowly changing recently with more semi-annual payments, (fiscal year from Jan to Dec)
Japan, big waves of dividends ex-dates at quarter ends (24 dec, 24 mar, etc., most of it in September end), but the amount can change between the ex-date and the payment date which can be 2 to 3 months later (fiscal year end in march) so you need to double guess the estimate...
Taiwan, China, dividend period in the summer with fiscal year end in December
US, no particular dividend season
So from these examples you could deduce that dividend ex-date season is usually 3 to 6 months after fiscal year end, when there is a dividend season.