## Formula in Excel 365

### How to format negative timestamps

Excel supports different formats for positive and negative numbers. You can combine text and formatted values to make the display more presentative. Another numeric format is a timestamp, and you can find a difference between two timestamps and display it in days, hours, and minutes. However, Excel does not handle well negative timestamp differences.

### Calculating the number of days between two dates

If you need to count the number of dates between two dates in Excel, you don't need to use

**DATEDIF**and other Excel date manipulation functions. Date in Excel isn't a separate type, but a number with proper formatting. The integer part of this number represents days since the fixed moment for all dates. Subtract one date from another, and you will get the number of days between two dates. Also, you can add or subtract an integer from the date, and get the date in the future or the past.### How to create a break-even chart in Excel

A revenue the company generates from selling the products or providing the services should cover the
fixed costs, variable costs, and leave a contribution margin. The point where the total operating
margin (the difference between the price of the product or service and the variable costs per item
or customer) covers the fixed costs is called a

**break-even point**.### Different rounding effects in Excel

When you work with digits, it's crucial how you round them. It doesn't depend on what exactly you
are rounding - decimals, thousands, or millions. You can see very different amounts after summing
the figures, rounded in different ways:

### How to calculate age in Excel

To calculate the age of a person, a pet, a project, or even some device, you need to compute a
number of complete years. The issue is that it doesn't seem enough to calculate a year's difference.
Excel proposes a very useful formula that can help you to calculate that very fast.

### How to calculate a lifetime in Excel

Sometimes it is necessary to calculate a lifetime for some devices, things. Usually, a lifetime
calculates in full months, for example, to check a warranty or guaranty period. Excel proposes
a very useful formula that can help calculate that time.

### How to calculate how many days left to or passed from the specific date in Excel

For some projects or tasks, you might need to calculate how many days, months, or years left to some date or how many days, months, or years passed from some date till today. Excel proposes a very useful formula that can help you to calculate that very fast.

### How many work weeks left to or passed from the specific date in Excel

When you plan a project, you can need to calculate a number of workdays or full workweeks between the start and end dates, or how many workdays or workweeks left/passed. This tip is about an easy and fast way of calculation of full workweeks for weeks from Monday to Sunday.

### How many weeks left to or passed from the specific date in Excel

When you plan a trip, project, etc. you can need to calculate a number of days or weeks between the start and end dates, or how many days or weeks left/passed. This tip is about an easy and fast way of complete weeks calculation.

### How to calculate the number of work days for a four-day workweek

When calculating the difference between two dates, you may want to exclude weekends and holidays. Excel proposes a standard formula for
calculating the number of workdays for standard, five-day workweek. Also, Excel proposes a formula for
calculating the number of workdays for different five-day workweek or six-day workweek.