Tom, your best times to call are the first couple hours of daylight followed by the last 2 hours of daylight.You can call them at lunch time but it will not be as effective as the early morning and late evening hours.When using a electronic caller always start out on a low volume.If you do not, you run the risk of blowing out a yote that is already close to you.You would not believe how good a coyotes hearing is.One thing you do not want to do is educate a coyote,they have a amazing capability to learn.In my opinion,electronic callers have their place where the ranges are long and it is real windy.Other wise try mastering the mouth blown call as you can vary the pitch and "emotion".And more importantly you can shut the mouth call of quick. Yotes catch on to the same ole, same ole, dying rabbit .Mix it up.