I love shortcuts a lot. They are the most important tool in my productivity tool belt. Helping me to speed things up immensely. Here are the most important shortcuts that I use in Excel all the time:
The first two shortcuts are for inserting the current time and date when tracking my hours for a client in my contractor work. Previously, I looked up the date and time on the system clock and typed them in. This took only a few seconds, but when you try to leave a busy commuter train every second counts. Today, they are just a shortcut away.
Current Date and Time
To Insert the current date in Excel, press Ctrl+; (semi-colon) at the same time on both Windows and the Mac
To insert the current static time in Excel, press Ctrl+Shift+; (semi-colon) at the same time on Windows or ⌘+; (command plus semi-colon) on Mac.
Copy cell content from the above or from the left
Sometimes, I just need quickly duplicated content form the above or from the left cell. Using the clipboard is a good way to do it, but if you need something faster then here are the shortcuts I use duplicating existing content
To copy cell content from the left of your current cell in Excel hit Ctrl+R on Both Windows and Mac.
To copy cell content form the top of your current cell in Excel hit Ctrl+D on both Windows and Mac.