When the Church of Jesus Christ of Latter-day Saints was in its pioneer days, leadership callings could last for years and years. My grandfather was Ward Sunday School President and I got the impression that it spanned many years. Bishops could be in place for 25 years or more.
Things changed. When I was a young mother, leadership callings in the church lasted for a year or a year and a half, (though Bishops were there longer.) I also was often released from any callings right after my children were born and had a respite for a few months. This was not unusual.
The pendulum has swung back. I see many people staying in their callings for many, many years. I was Relief Society President for 5 years, our primary president has been in her calling for about 7, the Young Women's President about 4 and if you have a lesser known calling you can be there for 10 years or more. I have been ward choir pianist for approximately 10 years and I suspect I'll be there longer as it depends on a talent that is scarce in our ward. I am a ward organist for the same reason and expect to be there for a long time, though this is not new, I've known lots of career organists in many wards.
Also, a pregnant mom and new mom are expected to continue in their position unless she or her baby have health issues.
No reason for this post, but I just was thinking about how things change.