I have use kaluah for years and it is an important part of my reminders of holy days, but what is more important is multiple yarzeits I have as annual reminders.
This changes annually. What is a free substitute for private use.
I have been using Kaluach3 for many, many years.
The only problem that I have found was trying to edit or add a location.
But today I discovered a problem with the calculation of the correct times for Erev Pesach: sof z'man achilat matza, and sof z'man bi'ur chametz.
The calculations that Kaluach3 provides are off by about 40 minutes for the former, and about 20 minutes for the latter.
And, there is no one to fix the problem.
So I just have to keep that in mind, and do the calculations myself.
This changes annually. What is a free substitute for private use.
The only problem that I have found was trying to edit or add a location.
But today I discovered a problem with the calculation of the correct times for Erev Pesach: sof z'man achilat matza, and sof z'man bi'ur chametz.
The calculations that Kaluach3 provides are off by about 40 minutes for the former, and about 20 minutes for the latter.
And, there is no one to fix the problem.
So I just have to keep that in mind, and do the calculations myself.