Mars does not always pass through Libra in one go. When it turns retrograde near the boundary it backs out into the previous sign and returns months later, which splits a single visit into separate windows. Most almanacs quote one date range and lose that.
12 August 1993 → 27 September 1993Past
21 July 1995 → 7 September 1995Past
3 January 1997 → 8 March 1997Past
19 June 1997 → 14 August 1997Re-entry after retrograde
27 November 1998 → 26 January 1999Past
5 May 1999 → 5 July 1999Re-entry after retrograde
4 November 2000 → 23 December 2000Past
15 October 2002 → 1 December 2002Past
26 September 2004 → 11 November 2004Past
8 September 2006 → 23 October 2006Past
19 August 2008 → 4 October 2008Past
29 July 2010 → 14 September 2010Past
3 July 2012 → 23 August 2012Past
7 December 2013 → 26 July 2014Past
12 November 2015 → 3 January 2016Past
22 October 2017 → 9 December 2017Past
4 October 2019 → 19 November 2019Past
14 September 2021 → 30 October 2021Past
27 August 2023 → 12 October 2023Past
6 August 2025 → 22 September 2025Past
15 July 2027 → 2 September 2027Upcoming
21 December 2028 → 7 April 2029Upcoming
5 June 2029 → 7 August 2029Re-entry after retrograde
21 November 2030 → 15 January 2031Upcoming
30 October 2032 → 17 December 2032Upcoming
11 October 2034 → 26 November 2034Upcoming
21 September 2036 → 6 November 2036Upcoming
3 September 2038 → 19 October 2038Upcoming
14 August 2040 → 29 September 2040Upcoming
24 July 2042 → 9 September 2042Upcoming
19 January 2044 → 12 February 2044Upcoming
25 June 2044 → 17 August 2044Re-entry after retrograde
30 November 2045 → 4 February 2046Upcoming
12 April 2046 → 15 July 2046Re-entry after retrograde
7 November 2047 → 27 December 2047Upcoming
17 October 2049 → 4 December 2049Upcoming
29 September 2051 → 14 November 2051Upcoming
10 September 2053 → 25 October 2053Upcoming
22 August 2055 → 7 October 2055Upcoming
1 August 2057 → 17 September 2057Upcoming
8 July 2059 → 27 August 2059Upcoming