How much TV time or IPAD time do you limit to your toddler? How much is too much?

I agree on moderation also. For my girl she won't focus on tv for long even if I on for a few hours cos she only watch selective shows & songs which she like. But for iPad n tv I limit to half hour & especially before sleep will strictly no no. Cos it will become a habit & affect their sleep so I only allow her watch iPad n iPhone when I need to do something or she earn it.