When the sun shines brightly , it provides a great chance to get outdoor things done . Like making hay ! At least , that is what farmers from the past would say . “Make hay while the sun shines .” This idiom is very old , dating back to Medieval times . Rain would often ruin the process of making hay . So , farmers had no choice but to make hay when the sun was shining . Today , we all use this expression , not just farmers . When conditions are perfect to get something done , we can say , “It's a good idea to make hay while the sun shines .” In other words , you are taking advantage of a good situation or of good conditions . You are making the most of your opportunities . These all mean “making hay while the sun shines .” Now listen while I use this expression with my friend Bryan . Say , when is your husband coming home ? Not for another two weeks . That's a long time ! How are you spending your time alone ? I am finally getting some home improvement projects done . You know , moving some furniture , painting some rooms , cleaning closets … That's a lot of work for one person . Why don't you wait for your husband to come home ? It's easier to do it by myself . I'm getting everything done that I can't do with other people around . And sometimes we use this expression to mean we beat someone to the punch , or we got ahead of someone else . And other times you make hay while the sun shines to make good use of the chance to do something while it lasts . You are being opportunistic – taking advantage of a good opportunity . For example , my friend Ozzy was sick for a week and could not go to work . So , his co-worker Sarah -- who doesn't like him -- took advantage of his illness and stole his project ! Talk about making hay while the sun shines . Sometimes when you make hay while the sun shines you are staying ahead of a problem – like in this example : Hey , do you want to go hiking with me and my friends this weekend ? The weather is going to be beautiful ! I wish I could . But I have to finish my taxes . It's the last weekend before they're due . Oh , that's too bad . What about your taxes ? My taxes are done . I was off from work a couple of weeks ago and made hay while the sun shined . I got all of it done ! I wish I would have taken advantage of my time off last week . All I did was lay around the house . You should know that sometimes we only use parts of this expression . You might hear someone simply say they were “making a little hay .” The meaning is still there , even if all the words aren't . But join us again next week . You can listen while you're making dinner or riding to work . Yeah , make hay while the sun shines .