Calculate the end/ to figure out the end (outcome)/ (those who figure out the end/ reckoners of the end of days)
He tried to calculate when the Messiah would come. He was concerned with calculating when the 'end of days' would come, the period of the "last days" mentioned in the books of the prophets. A person who does this is called a 'counter of the end' or 'counter of times'. In the question: 'Count the end' means counting time later.
("Woe to the end-time calculators, who used to say: Since the end has arrived and he has not come, he will never come again. Rather, wait for him, as it is said: 'If he tarries, wait for him'" — Sanhedrin 97b; and likewise: "For this the sages, of blessed memory, warned against end-time calculators and against setting dates for the Messiah's coming, lest they mislead the masses and plant doubt in their hearts when that time comes and the Messiah has not come" — Maimonides, Epistle to Yemen, in the translation of R. Shmuel Ibn Tibbon, 421; and likewise: "One who charges interest upon interest, calculates times, counts numbers for the hours, and makes days into weeks" — Shalom Aleichem, Geese, 138)
Translation
Expression (Hebrew)
חִישֵּׁב אֶת הַקֵּץ (מְחַשֵּׁב קִיצִּין, מְחַשֵּׁב עִיתִּים)
Definition (Hebrew)
נִיסָּה לְחַשֵּׁב מָתַי יָבוֹא הַמָּשִׁיחַ. עָסַק בְּחִשּׁוּבִים מָתַי יָבוֹא 'קֵץ הַיָּמִים', תְּקוּפַת "אַחֲרִית הַיָּמִים" הַמֻּזְכֶּרֶת בְּסִפְרֵי הַנְּבִיאִים. אָדָם הָעוֹסֵק בְּכָךְ מְכוֹנָה 'מְחַשֵּׁב קִצִּין' אוֹ 'מְחַשֵּׁב עִתִּים'. בְּהַשְׁאָלָה: 'חִשֵּׁב אֶת הַקֵּץ' מַשְׁמָע סֵפֶר אֶת הַזְּמַן לְאָחוֹר.
("תִּפַּח עַצְמָן שֶׁל מְחַשְּׁבֵי קִצִּין, שֶׁהָיוּ אוֹמְרִים: כֵּיוָן שֶׁהִגִּיעַ אֶת הַקֵּץ וְלֹא בָּא- שׁוּב אֵינוֹ בָּא. אֶלָּא חַכֵּה לוֹ, שֶׁנֶּאֱמַר אִם יִתְמַהְמָהּ חַכֵּה לוֹ"-סַנְהֶדְרִין צז ע"ב, וְכֵן:"וְלָזֶה הִזְהִירוּ הַחֲכָמִים זַ"ל מְחַשֵּׁב קִצִּים וּמְמַנּוֹת זְמַנִּים לְבִיאַת הַמָּשִׁיחַ,מִפְּנֵי שֶׁיַּכְשִׁיל הֶהָמוֹן וְיַכְנִיס סָפֵק בְּלִבָּם כְּשֶׁיָּבוֹא הַזְּמַן הַהוּא וְלֹא בָּא הַמָּשִׁיחַ"- הָרַמְבָּ"ם/ אִגֶּרֶת תֵּימָן בְּתַרְגּוּם ר"ש אִבְּן תִּבּוֹן,421, וְכֵן:"זוֹקֵף רִבִּית עַל רִבִּית, מְחַשֵּׁב עִתִּים, מוֹנֶה מִסְפָּר לִשְׁעוֹת ןְעוֹשָׁה יָמִים כְּשֶׁבּוּעוֹת"-שָׁלוֹם עֲלֵיכֶם/ אֲוָזִים,קלח)