Mordechai seems to push Esther to entreat Achashveirosh right after telling her about Haman's decree (Esther 4:14)
אִם־הַחֲרֵ֣שׁ תַּחֲרִישִׁי֮ בָּעֵ֣ת הַזֹּאת֒ רֶ֣וַח וְהַצָּלָ֞ה יַעֲמ֤וֹד לַיְּהוּדִים֙ מִמָּק֣וֹם אַחֵ֔ר וְאַ֥תְּ וּבֵית־אָבִ֖יךְ תֹּאבֵ֑דוּ וּמִ֣י יוֹדֵ֔עַ אִם־לְעֵ֣ת כָּזֹ֔את הִגַּ֖עַתְּ לַמַּלְכֽוּת׃
This exchange took place in the month of Nissan, a full 11 months before Haman's decree was set to go into effect. For what reason did Mordechai feel the need to push Esther to act immediately?
As support for the preference towards waiting for an opportune time instead of forcing the matter it says in Eiruvin 13b
וכל הדוחק את השעה שעה דוחקתו וכל הנדחה מפני שעה שעה עומדת לו
And anyone who attempts to force the moment and expends great effort to achieve an objective precisely when he desires to do so, the moment forces him too, and he is unsuccessful. And conversely, anyone who is patient and yields to the moment, the moment stands by his side, and he will ultimately be successful.
(Translation [in bold] and commentary from Sefaria)
To preempt a possible answer I understand that the Jewish people were facing extermination and that it is important to act. I believe Esther understood that as well yet her initial response to Mordechai indicated that the current time was inopportune. Nevertheless Mordechai's response to her ignored (or perhaps disagreed with) her assessment and urged for immediate action not because of the threat faced ("salvation will come from another place").