$testVar = 'lower case text'

Changing cases in a string to title case, upper case, or lower case:

$Culture.ToTitleCase($testVar) || Output: Lower Case Text
$Culture.ToUpper($testVar) || Output: LOWER CASE TEXT
$Culture.ToLower($testVar) || Output: lower case text

$epochTime = '1575376470'
$regularTime = Get-Date

Convert epoch time to normal date:
ConvertFrom-EpochToNormal -InputEpoch $epochTime || Output: 03.12.2019 14:34:30 (date format depends on your locale settings)

Convert normal date to epoch:
ConvertFrom-NormalToEpoch -Date $regularTime || Output: 1552397119