Set Crawl Incremental/Full Properties using PowerShell

$ssaName="Search Service Application"

$context=[Microsoft.Office.Server.Search.Administration.SearchContext]::GetContext($ssaName)

 

$daily=New-Object Microsoft.Office.Server.Search.Administration.DailySchedule($context)

$daily.BeginDay="25"

$daily.BeginMonth = "1"

$daily.BeginYear = "2010"

$daily.StartHour = "2"

$daily.StartMinute = "30"

$daily.DaysInterval = "1"

$weekly=New-Object Microsoft.Office.Server.Search.Administration.WeeklySchedule($context)

$weekly.BeginDay="25"

$weekly.BeginMonth = "1"

$weekly.BeginYear = "2010"

$weekly.StartHour = "23"

$weekly.StartMinute = "15"

$weekly.WeeksInterval = "1"

 $contentsource = Get-SPEnterpriseSearchCrawlContentSource -SearchApplication $ssaName -Identity "Local SharePoint Sites"

$contentsource.IncrementalCrawlSchedule=$daily

$contentsource.FullCrawlSchedule=$weekly

$contentsource.Update()