I have some .png files named \'_tmp*.png\' and I want to convert them into a gif file by the convert command with imagemagick. So i could use
convert -delay 20
You can do it like this:
convert -delay 40 {1..9}.png -delay 300 10.png -delay 40 {11..14}.png animated.gif
Basically, you set the delay just before the image you want it to affect and it stays set until you change it.
If you want to set a variable delay, so that the first (i.e. black here) and the last frame (i.e. yellow here) are displayed longer, you can do this:
convert -size 300x200 xc:black xc:red xc:lime xc:blue xc:cyan xc:magenta xc:yellow -set delay '%[fx:t==(n-1) || t==0 ? 400 : 40]' result.gif