The Achronim ask on the above Gemara from the Gemara in Rosh Hashanah (11a). The Gemara in Rosh Hashanah cites a machlokes if the final geulah [redemption] will be in Nissan or in Tishrei. If the final geulah will be in Nissan or in Tishrei, why must one be worried all year round for the arrival of Moshiach, surely his fear should be limited to Nissan and Tishrei?
The Pischei Teshuvah (Yoreh De’ah 239:6) quotes the Turei Even in Rosh Hashanah who says that there are two times for when the final redemption may happen, בעתו - at the correct time, or אחישנה – at a delayed time. If Moshaich comes at the correct time (בעתו), then it will be in either Nissan or Tishrei, however, if he comes at the delayed time, then he may arrive any day. We have to be worried that perhaps the time of בעתו has already passed, and he may now arrive any day.
