In this day and age
Definition 1 of 1
Pro Tip 1/3Current Trends
Use it to reference current trends or common practices. 
In this day and age, most communication happens over social media.
Pro Tip 2/3Time Frame
It emphasizes the difference from past practices or attitudes. 
In this day and age, smoking in restaurants is generally frowned upon.
Pro Tip 3/3Technological Context
Often used to highlight technological advancements or modern lifestyles. 
In this day and age, having a smartphone is almost a necessity.